THE DECREE OF THE PRESIDENCY OF THE GOVERNMENT NUMBER 2484/1967, OF 21 SEPTEMBER ( OF 17 OCTOBER), WHICH APPROVES THE SPANISH FOOD CODE, PROVIDES THAT THEY MAY BE SUBJECT TO SPECIAL REGULATIONS SUBJECTS IN THE REGULATED.

REAL DECREE 667/1983, OF 2 MARCH ( OF 31), APPROVING THE TECHNICAL-SANITARY REGULATIONS FOR THE MANUFACTURE AND SALE OF FRUIT JUICES AND OTHER VEGETABLES AND THEIR DERIVATIVES, VARIOUS PARAMETERS TO BE MET BY THE GRAPE JUICE.

ON THE OTHER HAND, IN THE STATUTE OF THE VINEYARD, WINE AND SPIRITS, APPROVED BY LAW 25/1970, OF 2 DECEMBER, AND IN THE REGULATION THAT DEVELOPS IT, APPROVED BY DECREE 835/1972, OF 23 MARCH ( OF 11 OF APRIL), NUMEROUS PARAMETERS ARE CONTEMPLATED TO COMPLY WITH THE GRAPE JUICES.

FOR ALL OF THE ABOVE, IT IS NECESSARY TO ESTABLISH OFFICIAL METHODS OF ANALYSIS THAT GUARANTEE THE QUANTIFICATION OF THE AFOREMENTIONED PARAMETERS.

IN ITS VIRTUE, ON THE PROPOSAL OF THE MINISTERS OF ECONOMY AND FINANCE, OF INDUSTRY AND ENERGY, OF AGRICULTURE, FISHERIES AND FOOD, AND OF HEALTH AND CONSUMPTION, PREVIOUS MANDATORY REPORT OF THE INTERMINISTERIAL COMMISSION FOR THE MANAGEMENT FOOD AND EARS THE REPRESENTATIVES OF THE ORGANISATIONS CONCERNED,

THIS MINISTRY OF RELATIONS WITH THE COURTS AND THE GOVERNMENT SECRETARIAT HAS:

FIRST. THE METHODS OF ANALYSIS FOR GRAPE JUICE REFERRED TO IN ANNEX I ARE APPROVED AS OFFICIAL.

SECOND. WHERE THERE ARE NO OFFICIAL METHODS FOR CERTAIN ANALYSES, AND UNTIL SUCH METHODS ARE PROPOSED BY THE COMPETENT AUTHORITY AND NOTIFIED IN ADVANCE BY THE INTER-MINISTERIAL COMMISSION FOR FOOD MANAGEMENT, THE FOLLOWING MAY BE USED: APPROVED BY THE NATIONAL OR INTERNATIONAL BODIES OF RECOGNISED SOLVENCY.

REPEAL PROVISION

THE PROVISIONS OF EQUAL OR LOWER RANK WHICH ARE OPPOSED TO THIS ORDER ARE HEREBY REPEALED. # MADRID, 27 APRIL 1988.

ZAPATERO GOMEZ

EXCMOS. SRES. MINISTERS FOR HEALTH AND CONSUMER AFFAIRS, ECONOMY AND FINANCE, INDUSTRY AND ENERGY, AGRICULTURE, FISHERIES AND FOOD.

ANNEX I

OFFICIAL GRAPE JUICE ANALYSIS METHODS

INDEX

1. GRADO BRIX.

2. DENSITY.

3. PH.

4.

TOTAL ACIDITY.

5. VOLATILE ACIDITY.

6. SOLUBLE SOLIDS.

7. TOTAL SUGARS AND REDUCERS.

8. ASCORBIC ACID.

9. GLUCO/FRUCTOSE RATIO.

10.

TOTAL NITROGEN.

11. ETHYL ALCOHOL.

12. FORMOL INDEX.

13. PROLINA.

14. SORBIC ACID.

15. BENZOIC ACID.

16. HYDROXYMETHYLFURFURAL.

17.

ASHES.

18. MINERAL MATTER INSOLUBLE IN HYDROCHLORIC ACID AT 10 PER 100.

19. TOTAL PHOSPHORUS.

20. SULFATOS.

21 (A). SULFUROUS ANHYDRIDE.

22.

POTASSIUM.

23. SODIO.

24. ARSENIC.

25. IRON.

26. Lead.

27. THIS YEAR.

28. COBRE.

29. CNC.

1. GRADO BRIX

1.1 PRINCIPLE

MEASURE OF THE REFRACTIVE INDEX AND CONVERSION TO DEGREES BRIX BY THE ATTACHED TABLES.

1.2 MATERIAL AND APARATOS

1.2.1 REFRACTOMETER PROVIDED WITH EQUIPMENT REQUIRED TO MAINTAIN TEMPERATURE AT 20 C.

1.2.2 FLASKS OR GLASS CONTAINERS THAT ARE HERMETICALLY CLOSED.

1.3 PROCEDURE

PLACE THE REFRACTOMETER IN AN ILLUMINATED PLACE WITH DIFFUSE LIGHT OR A SOURCE OF ARTIFICIAL LIGHT.

CIRCULATE WATER AT CONSTANT TEMPERATURE TO 20 C THROUGH THE PRISMS OF THE REFRACTOMETER. ADJUST THE INSTRUMENT BY PLACING A FEW DROPS OF DISTILLED WATER BETWEEN THE PRISMS. THE REFRACTIVE INDEX MUST BE 1.3330; IF NOT, CORRECT THE READING.

PLACE THE GRAPE JUICE IN A HERMETICALLY CLOSED CONTAINER IN A BATH AT 20 C AND WAIT FOR IT TO REACH THAT TEMPERATURE. TAKE WITH A PIPETTE A LITTLE GRAPE JUICE AND PUT A FEW DROPS BETWEEN THE PRISMS OF THE REFRACTOMETER. MEASURE THE REFRACTIVE INDEX.

1.4 EXPRESSION OF RESULTS

FROM THE VALUE OBTAINED FROM THE REFRACTIVE INDEX IS OBTAINED THE BRIX GRADE BY TABLE I.

1.5 REMARKS

1.5.1 IF ANOTHER TEMPERATURE IS USED TO MEASURE THE REFRACTIVE INDEX, USE TABLE II FOR TEMPERATURE CORRECTION AT 20 C.

1.6 REFERENCES

OFFICIAL METHODS OF ANALYSIS, AOAC-1984.

2. DENSITY

2.1 PRINCIPLE.

THE DENSITY (20 /20 C) OF THE LIQUID TO BE ANALYZED IS DETERMINED BY MEANS OF THE PICNOMETER.

2.2 MATERIAL AND APARATOS.

2.2.1 STUDY.

2.2.2 DESECATOR.

2.2.3 YEAR TO 20 C.

2.2.4 1/10 MG SENSITIVE ANALYTICAL SCALE.

2.2.5 50 ML REISCHUER PICNOMETER OR SIMILAR.

THE REISCHAUER PICNOMETER CONSISTS OF A 50 ML CAPACITY FLASK, CLOSED WITH A GRINDING CAP FITTED WITH A 6 CM LONG NECK AND 4 MM INSIDE DIAMETER.

2.2.6 ERLENMEYER 500 ML.

2.2.7 FUNNEL 10 CM IN DIAMETER.

2.2.8 CAPILLARY TUBES.

2.3 REAGENTS.

2.3.1 CHRONIC MIXING.

2.3.2 FILTER PAPER.

2.4 PROCEDURE.

IF THE LIQUID TO BE ANALYZED CONTAINS AN APPRECIABLE AMOUNT OF CARBONIC GAS, IT IS NECESSARY TO COMPLETELY REMOVE THIS ONE BY STIRRING STRONGLY IN AN ERLENMEYER AND TO FILTER IT BELOW BY MEANS OF A FILTER COVERED WITH A WATCH GLASS.

REPEAT THIS OPERATION, IF NECESSARY.

2.4.1 DETERMINATION OF THE WEIGHT OF THE EMPTY PICNOMETER: CLEAN THE PICNOMETER WITH HOT CHROMIC MIXTURE, IF NECESSARY; THEN RINSE CAREFULLY WITH DISTILLED WATER. DRY FOR THREE HOURS ON THE STOVE AT 105-108 C. COOL IN DESICCATOR TO ROOM TEMPERATURE AND EXPRESS THE RESULT WITH FOUR DECIMAL PLACES.

2.4.2 DETERMINATION OF THE WEIGHT OF THE PICNOMETER FULL OF WATER: FILL THE PICNOMETER TO THE MARK WITH DISTILLED WATER. TAPAR AND PUT IT IN A WATER BATH AT 20 C FOR TWENTY MINUTES. BEING THE TEMPERATURE BALANCED, MAKE UP THE PICNOMETER (ALWAYS SUBMERGED IN THE WATER BATH) WITH THE HELP OF A CAPILLARY.

DRY THE EMPTY PART OF THE NECK OF THE PICNOMETER THROUGH THE FILTER PAPER.

PLACE THE STOPPER, REMOVE THE PICNOMETER FROM THE WATER BATH, AND DRY CAREFULLY.

THE WEIGHT OF THE WATER-FILLED PICNOMETER SHOULD BE DETERMINED WITH A PRECISION OF FOUR DECIMAL PLACES.

2.4.3 DETERMINATION OF THE WEIGHT OF THE PICNOMETER FULL OF SAMPLE: AFTER EMPTYING THE PICNOMETER, WASH SEVERAL TIMES WITH THE SAMPLE AND PROCEED AS IN 2.4.2, SUBTRACTING THE WATER BY GRAPE JUICE.

2.5 CALCULATIONS.

CALCULATE DENSITY 20 C/20 C BY APPLYING THE FOLLOWING FORMULA:

D = C-A/B-A

SIENIT:

A = EMPTY PICNOMETER WEIGHT.

B = PICNOMETER WEIGHT FULL OF WATER UP TO THE MARK.

C = PICNOMETER WEIGHT FILLED WITH LIQUID TO ANALYZE UP TO THE MARK.

THE DENSITY OBTAINED SHOULD BE EXPRESSED WITH A PRECISION OF FOUR DECIMAL PLACES.

2.6 REFERENCES.

FEDERATION INTERNATIONAL DES PRODUCTEURS DE JUS DE FRUITS.

METHOD NUMBER 1, 1968.

3. PH

3.1 PRINCIPLE.

POTENTIOMETRIC MEASUREMENT AT 20 C, AFTER REMOVAL OF CARBON DIOXIDE BY COLD AGITATION AND PARTIAL VACUUM.

3.2 MATERIAL AND APARATOS.

3.2.1 PH-METRO.

3.2.2 ELECTRO/S FOR PH MEASUREMENT.

3.3 REAGENTS.

3.3.1 SOLUTION BUFFER PH = 7; DISSOLVE 3,522 G OF POTASSIUM DIHYDROGEN PHOSPHATE (KH 2 PO 4); 14.020 G OF DISODIUM PHOSPHATE DISODIUM DODECAHYDRATE (NA 2 HPO 4 /4 12H 2 O) AND LEAD TO A LITRE WITH DISTILLED WATER.

3.3.2 SOLUTION BUFFER PH = 4; DISSOLVE 10,211 G OF POTASSIUM ACID PHTHALATE (KHC 6 H 4 OR 4) (DRYING ONE HOUR AT 105 C) IN A LITRE OF WATER DISTILLED AT 20 C.

3.4 PROCEDURE.

INTRODUCE A SUITABLE SAMPLE VOLUME INTO A KITASATE. CONNECT TO VACUUM WHILE AGITATING THE FLASK, TO THE REMOVAL OF CARBON DIOXIDE.

TAKE A SAMPLE VOLUME FREE OF CARBON DIOXIDE AND DETERMINE PH.

3.5 EXPRESSION OF THE RESULTS.

EXPRESS THE PH MEASURED AT 20 C WITH ONE OR TWO DECIMAL PLACES, ACCORDING TO THE ACCURACY OF THE APPARATUS.

3.6 REMARKS.

3.6.1 BEFORE EACH NEW MEASURE, CLEAN THE ELECTRODES WITH DISTILLED WATER AND DRY THEM WITH FILTER PAPER.

3.6.2 THE CALOMELIAN ELECTRODE MUST BE FILLED WITH TIME IN TIME OF A SATURATED SOLUTION OF CLK.

3.6.3 THE GLASS ELECTRODE MUST BE KEPT IN WATER AND THE ONE OF CALOMELANS IN A SATURATED SOLUTION OF CLK. THE COMBINED ELECTRODES MUST BE PRESERVED IN A CLK SATURATED SOLUTION.

3.6.4 THE CALIBRATION IS DONE WITH THE HELP OF THE TAMPON SOLUTIONS FOLLOWING THE PARTICULAR INDICATIONS OF THE MANUFACTURER OF THE DEVICE.

3.7 REFERENCES.

FEDERATION INTERNATIONAL DES PRODUCTEURS DE JUS DE FRUITS. METHOD NUMBER 11, YEAR 1968.

4.

TOTAL ACIDITY

4.1 PRINCIPLE.

POTENTIOMETRIC RATING AT PH = 8.1 OF THE ACIDITY OF THE GRAPE JUICE, AFTER ELIMINATION OF CARBON DIOXIDE.

4.2 MATERIAL AND APARATOS.

4.2.1 PH-METER WITH ELECTRODO/S FOR PH MEASUREMENTS.

4.2.2 MAGNETIC STIRRER.

4.3 REAGENTS.

4.3.1 0.1 N. SODIUM HYDROXIDE SOLUTION

4.4 PROCEDURE.

TAKE 20 ML OF THE GRAPE JUICE, FREE OF CARBON DIOXIDE, OBTAINED AS IN 3.4, AND BRING TO A GLASS OF ABOUT 100 ML CAPACITY. LAUNCH THE AGITATOR AND RATE WITH SOLUTION 4.3.1 UP TO PH 8.1 TO 20 C.

KEEP THE AGITATOR RUNNING DURING THE OPERATION, WHICH SHOULD LAST AT LEAST FIVE MINUTES.

4.5 CALCULATIONS.

CALCULATE THE TOTAL ACIDITY EXPRESSED IN MEQ/L, WITH AN APPROXIMATION OF 0,1 MEQ/L, OR IN GRAMS OF TARTARIC/L. ACID

TOTAL ACIDITY (MEQ/L) = 10 V/2

TOTAL ACIDITY (G TARTARIC/L ACID) = 0.75 V/2

SIENIT:

V = VOLUME, IN ML OF 0.1 N. SODIUM HYDROXIDE SOLUTION.

4.6 REFERENCES.

IL DES MÉTHODES INTERNATIONALES D' ANALYSE DES VINS O.I.V. A 10 (1969), 1-3.

5. VOLATILE ACIDITY

5.1 PRINCIPLE.

SEPARATION OF THE VOLATILE ACIDS FROM THE GRAPE JUICE BY ENTRAINMENT WITH WATER VAPOR, PREVENTING THE PRESENCE OF CARBON DIOXIDE IN THE DISTILLATE. ASSESSMENT WITH SODIUM HYDROXIDE SOLUTION, DISCOUNTING THE CONTENTS OF SORBIC ACID AND FREE AND TOTAL SULPHUR DIOXIDE.

5.2 MATERIAL AND APARATOS.

5.2.1.1 3,500 ML STEAM GENERATOR FLASK (A).

THE WATER CONDENSED IN THE JUNCTION TUBE OF THE FLASK WITH THE BORER IS PURGED BY THE PURGATOR (C).

5.2.1.2 BORBOTER (B). CYLINDRICAL TUBE OF 3 CM IN DIAMETER AND 27 CM IN HEIGHT. THIS TUBE RESTS ON A 15 CM DIAMETER ASBESTOS DISC WITH A CENTRAL HOLE OF 29 MM. THE TUBE (D) BY WHICH THE STEAM ENTERS THE BORER MUST BE 1 CM FROM THE BOTTOM.

5.2.1.3 GRINDING COLUMN (E). 20 MM DIAMETER AND 50 CM HIGH.

5.2.1.4 WEST REFRIGERANT (F). 40 CM USEFUL LENGTH, VERTICALLY POSITIONED.

5.3 REAGENTS.

5.3.1 SODIUM HYDROXIDE SOLUTION 0.05 N.

5.3.2 PHENOLPHTHALEIN SOLUTION AT 1 PER 100 IN NEUTRAL ETHANOL.

5.3.3 0.01 N. IODO SOLUTION

5.3.4 STARCH ENGRUB SOLUTION.

5.3.5 BORAX SATURADA SOLUTION.

5.4 PROCEDURE.

FEED THE STEAM GENERATOR WITH LIME WATER OR CLEAN BARITA WATER, KEEPING IT UP TO ABOUT 2/3 OF ITS VOLUME. PUT 20 ML OF CARBONATED GRAPE JUICE IN THE BORBOTTLE, AS IN 3.4.

ADD A 0.5 G OF TARTARIC ACID TO THE GRAPE JUICE, START THE STEAM GENERATOR, KEEPING THE OUTLET OF THE STEAM PURGATOR OPEN; AFTER CLOSING, HEAT THE BORER. DURING THE OPERATION THE HEATER IS REGULATED SO THAT THE VOLUME OF LIQUID IN THE BORER DOES NOT PASS SIGNIFICANTLY FROM THE INITIAL TWENTY MINUTES.

DISTIL IN ABOUT ONE-FIFTEEN MINUTES 250 ML.

ASSESS WITH SODIUM HYDROXIDE SOLUTION 0.05 N IN THE PRESENCE OF TWO DROPS OF PHENOLPHTHALEIN AS AN INDICATOR.

ASSESS FREE SULPHUR DIOXIDE IN THIS SAME DISTILLATE, ADDING AT THE END OF THE PREVIOUS ASSESSMENT A DROP OF PURE HYDROCHLORIC ACID, TO BE FURTHER ACIDIC, BY VALUING THE FREE SULPHUR DIOXIDE WITH IODINE SOLUTION 0,01 N, ALSO ADDING 2 ML OF STARCH SOLUTION AS AN INDICATOR AND A POTASSIUM IODIDE CRYSTAL.

TO DETERMINE SULFUR DIOXIDE COMBINED WITH ACETALDEHYDE, ADD 20 ML OF BORTAX SATURATED SOLUTION (LIQUID TAKES A PALE PINK COLOR) AND VALUE AGAIN WITH 0.01 N. IOD SOLUTION.

5.5 CALCULATIONS.

CALCULATE THE VOLATILE ACIDITY EXPRESSED IN BEING:

V = VOLUME, IN ML USED FOR MEQ/L OR IN G ACITICO/L.

VOLATILE ACIDITY (MEQ/L) = 5 (V/2-V ' /10-V " /20)

VOLATILE ACIDITY (G/L ACETIC ACID) = 0.3 (V/2-V ' /10-V " /20)

SIDIO HYDROXIDE SOLUTION 0.05 N.

V' = VOLUME, IN ML OF IODO 0,01 N USED IN THE OXIDATION OF FREE SULPHUR DIOXIDE.

V '' = VOLUME, IN ML OF IODO 0,01 N USED IN THE OXIDATION OF SULPHUR DIOXIDE COMBINED WITH ACETALDEHYDE.

5.6 REMARKS.

5.6.1 THE DETERMINATION OF THE VOLATILE ACIDITY SHALL BE MADE IMMEDIATELY AFTER THE OPENING OF THE CONTAINER.

5.6.2 IN THE DISTILLATION OF THE GRAPE JUICE FOR THE DETERMINATION OF THE VOLATILE ACIDITY, THE SISTER ACID PASSES ALMOST ENTIRELY TO THE DISTILLATE, DISTORTING THE RESULT OF THE ANALYSIS. MAKE THE CORRECTION. 100 MG SORBIC ACID EQUALS 0.892 MEQ = 0.0535 GR OF ACETIC ACID.

5.6.3 CORRECTION OF VOLATILE ACIDITY IS PERFORMED ACCORDING TO THE RULE OF JAULMES, AND THE ENTIRE CONTENT OF FREE SULPHUR DIOXIDE AND HALF D

6. SOLUBLE SOLIDS

(DRY EXTRACT)

THE CONTENT IN SOLUBLE SOLIDS EXPRESSED IN G/L IS CALCULATED FROM THE VALUE OF THE DENSITY, OBTAINED ACCORDING TO THE OFFICIAL METHOD NUMBER 2 AND USING THE ATTACHED TABLE.

(OMITTED BOX)

7. TOTAL SUGARS AND REDUCERS

7.1 PRINCIPLE.

PRIOR ELIMINATION OF ALL REDUCING SUBSTANCES OTHER THAN SUGARS DUE TO DEFECATION, INVERSION AND SUBSEQUENT ASSESSMENT BASED ON THE REDUCTION OF SUGARS ON A CUPRO-ALKALINE SOLUTION.

7.2 MATERIAL AND APARATOS.

7.2.1 REQUIRED MATERIAL FOR VOLUMETRIES.

7.2.2 WATER YEAR.

7.2.3 ERLENMEYER 300 ML WITH REFLUX COOLANT.

7.3 REAGENTS.

7.3.1 SULFURIC ACID SOLUTION AT 25 PER 100 BY VOLUME.

7.3.2 HYDROCHLORIC ACID (D = 1,16 G/ML).

7.3.3 GLACIAL ACETIC ACID OF AT LEAST 96 PER 100 OF WEALTH.

7.3.4 POTASSIUM HYDROXIDE SOLUTION AT 30 PER 100.

7.3.5 POTASSIUM IODIDE SOLUTION AT 30 PER 100.

7.3.6 STARCH SOLUTION AT 1 PER 100.

7.3.7 CARREZ I SOLUTION:

DISSOLVE 150 G OF POTASSIUM TRIHYDRATE HEXACYANOFERDE (II)

(K 4 (FE (CN) 6) 3H 2 O) IN A WATER LITRO.

7.3.8 CARREZ II SOLUTION:

DISSOLVE 300 G OF ZINC SULFATE HEPTAHYDRATE (ZN SO 4 3/4 7H 2) IN A WATER LITRO.

7.3.9 LUFF-SCHOORL SOLUTION:

DISSOLVE 50 G OF CITRIC ACID IN 500 ML OF WATER AND 143.7 G OF ANHYDROUS SODIUM CARBONATE IN 350 ML OF WARM WATER; WHEN COOLED, CAREFULLY MIX BOTH SOLUTIONS. DISSOLVE 25 G OF COPPER SULPHATE (II) PENTAHYDRATE (CU SO 4 3/4 5H 2 O) IN 100 ML OF WATER. ADD TO THE PREVIOUS SOLUTION AND MAKE UP TO ONE LITRE WITH WATER.

7.3.10 SODIUM THIOSULFATE SOLUTION 0.1 N.

7.3.11 PHENOLPHTHALEIN SOLUTION: DISSOLVE 0.1 G PHENOLTALEIN IN 100 ML ETHANOL.

7.4 PROCEDURE.

7.4.1 PREPARATION OF THE SAMPLE: TAKE 25 ML PIPETTE OF THE SAMPLE IN A 500 ML VOLUMETRIC FLASK. ADD 150 ML OF WATER AND 5 ML OF THE CARREZ I SOLUTION; MIX AND ADD 5 ML OF THE CARREZ II SOLUTION. MIX AND MAKE UP WITH WATER. LEAVE AT REST TEN MINUTES AND FILTER.

7.4.2 INVESTMENT OF SUGARS: TAKE 25 ML PIPETTE OF THE PREPARED SAMPLE ACCORDING TO (7.4.1) AND LEAD TO A 100 ML OR 200 ML FLASK, DEPENDING ON THE DILUTION TO BE USED. DILUTE WITH WATER UP TO 75 ML AND ADD 5 ML OF HYDROCHLORIC ACID (7.3.2). BEFORE FIVE MINUTES TAKE IT TO 67-70 C IN A WATER BATH, KEEP IT FOR FIVE MINUTES AT THAT TEMPERATURE. CHECK THE TEMPERATURE WITH A THERMOMETER INTRODUCED IN THE DISSOLUTION. IMMEDIATELY COOL THE FLASK TO 20 C, REMOVE THE THERMOMETER AND CLEAR IT. NEUTRALISE THE CONTENT WITH POTASSIUM HYDROXIDE SOLUTION (7.3.4), USING PHENOLPHTHALEIN AS AN INDICATOR. ADD A FEW DROPS OF ACETIC ACID UNTIL THE COLOR OF THE PHENOLPHTHALEIN DISAPPEARS.

MAKE UP THE FLASK WITH WATER.

7.4.3 DETERMINATION OF TOTAL SUGARS: THE SAMPLE SOLUTION MUST NOT CONTAIN MORE THAN 50 MG OF REDUCING SUGARS. PIPETTE 25 ML OF THE SAMPLE PREPARED ACCORDING TO (7.4.2) ON A FLASK CONTAINING 25 ML OF LUFF SCHOORL SOLUTION (7.3.9). ADD THE GLASS BEADS TO THE FLASK AND CONNECT THE REFLUX COOLANT.

HEAT THE FLASK WITH A POWERFUL FLAME FOR TWO MINUTES AND KEEP IT BOILING FOR TEN MINUTES. COOL IMMEDIATELY IN WATER. WHEN COMPLETELY COLD, ADD 10 ML OF THE POTASSIUM IODIDE SOLUTION (7.3.5) AND, WITH CARE, 25 ML OF THE SULFURIC ACID SOLUTION (7.3.1). ADD 2 ML OF THE STARCH SOLUTION (7.3.6) AND RATE THE CONTENTS OF THE FLASK WITH SODIUM THIOSULFATE SOLUTION (7.3.10) UNTIL A CREAMY WHITE COLOUR IS OBTAINED. IF LESS THAN 5 ML WERE USED IN THE ASSESSMENT, REPEAT THE DETERMINATION USING A DILUTION OF THE MOST APPROPRIATE SAMPLE.

PERFORM A BLANK DETERMINATION IN PARALLEL, EMPLOYING 25 ML OF WATER.

7.4.4 REDUCING SUGARS: FOR THE DETERMINATION OF REDUCING SUGARS FOLLOW THE SAME PROCEDURE BY SUPPRESSING THE INVERSION (7.4.2).

7.5 CALCULATIONS.

BE D THE DIFFERENCE BETWEEN THE SPENT OF SODIUM THIOSULFATE BY THE TARGET AND THE AMOUNT SPENT BY THE SAMPLE.

THE CONCENTRATION OF TOTAL SUGARS EXPRESSED IN GLUCOSE IS OBTAINED FROM THE VALUE D IN THE TABLE, INTERPOLATING AS NECESSARY AND MULTIPLYING BY THE DILUTION FACTOR.

7.6 REFERENCES.

FEDERATION INTERNATIONAL DES PRODUCTEURS DE JUS DE FRUITS. METHOD NUMBER 4. YEAR 1985.

TABLE I

(OMITTED BOX)

8. ASCORBIC ACID

8.1 PRINCIPLE.

SEPARATION, IDENTIFICATION AND QUANTIFICATION OF ASCORBIC ACID BY HIGH EFFICACY LIQUID CHROMATOGRAPHY, DETECTING IT IN ULTRAVIOLET AT 268 NM.

8.2 MATERIAL AND APARATOS.

8.2.1 SAMPLE AND SOLVENT FILTRATION EQUIPMENT TO REMOVE PARTICLES ABOVE 0.5 MM.

8.2.2 LIQUID CHROMATOGRAPH EQUIPPED WITH VARIABLE WAVELENGTH ULTRAVIOLET DETECTOR AND LOGGER.

8.2.3 COLUMN NH 2 LICHORSORB 250 X 4.6 MM FR 10 MM OR LIKE.

8.3 REAGENTS.

8.3.1 STANDARD SOLUTION OF 300 MG/L ASCORBIC ACID, PREPARED IN THE DAY AND PRESERVED IN THE TOPAZ COLOUR FLASK.

8.3.2 SOLUTION TO: BUFFER PHOSPHATE, PH 3.5.

DISSOLUTION 0.005 M POTASSIUM DIHYDROGEN PHOSPHATE (KH 2 PO 4): FILTER THIS SOLUTION

CON (8.2.1).

8.3.3 SOLUTION B: ACETONITRILE FOR HPLC.

8.4 PROCEDURE.

8.4.1 GUIDANCE CHROMATOGRAPHIC CONDITIONS:

MOBILE PHASE: PHOSPHATE/ACETONITRILE BUFFER:

60/40 (V/V).

FLOW: 1 ML/minute.

8.4.2 CALIBRATION: INJECT 10 TO 20 ML OF THE STANDARD SOLUTION INTO THE CHROMATOGRAPH (7.3.1) AND CALCULATE THE RESPONSE FACTOR.

RESPONSE FACTOR (F) = CO/AP

SIENIT:

CO = CONCENTRATION IN MG/L OF ASCORBIC ACID.

AP = PEAK AREA IN THE PATTERN SOLUTION CHROMATOGRAM.

8.4.3 DETERMINATION: HOMOGENIZE. FILTER BY (8.2.1) AND INJECT FROM 10 TO 20 ML IN THE CHROMATOGRAPH.

8.5 CALCULATIONS.

ASCORBICO ACID CONTENT, EXPRESSED IN MG/L (WITHOUT DECIMALS), WILL BE OBTAINED BY USING THE FOLLOWING FORMULA:

ASCORBICO ACID (MG/L) = F X AC

SIENIT:

F = RESPONSE FACTOR.

AC = ASCORBIC ACID PEAK AREA IN THE SAMPLE.

8.6 REMARKS.

8.6.1 THE DETERMINATION OF ASCORBIC ACID SHALL BE PERFORMED IMMEDIATELY AFTER THE OPENING OF THE CONTAINER.

8.6.2 WITH THIS METHOD IS NOT DETERMINED DEHYDROASCORBIC ACID.

9.

GLUCOSE FRUCTOSE RATIO

9.1 PRINCIPLE.

SEPARATION, IDENTIFICATION AND QUANTIFICATION OF GLUCOSE AND FRUCTOSE BY HIGH EFFICACY LIQUID CHROMATOGRAPHY, WITH REFRACTIVE INDEX DETECTOR.

9.2 MATERIAL AND APARATOS.

9.2.1 SAMPLE AND SOLVENT FILTRATION EQUIPMENT TO REMOVE PARTICLES ABOVE 0.5 MM.

9.2.2 LIQUID CHROMATOGRAPH EQUIPPED WITH REFRACTIVE INDEX DETECTOR AND LOGGER.

9.2.3 SUGAR-PACK COLUMN OR OTHER COLUMN ALLOWING FOR THE SEPARATION OF GLUCOSE AND FRUCTOSE.

9.2.4 OVEN FOR COLUMN.

9.3 REAGENTS.

9.3.1 GLUCOSE AND FRUCTOSE STANDARD SOLUTION 10 PER 100 (P/V).

9.4 PROCEDURE.

9.4.1 GUIDANCE CHROMATOGRAPHIC CONDITIONS FOR THE SUGAR-PACK COLUMN:

MOBILE PHASE: SOLUTION OF 20 MG/L OF CALCIUM ACETATE OR EDTA-CA IN DISTILLED AND DEIONIZED WATER.

FLOW: 0.4-0.5 ML/MIN.

OVEN TEMPERATURE: 90-95 C.

9.4.2 CALIBRATION: INJECT A KNOWN QUANTITY OF THE STANDARD SOLUTION INTO THE CHROMATOGRAPH AND CALCULATE THE RESPONSE FACTORS.

RESPONSE FACTOR (F)

SIENIT:

CO = CONCENTRATION IN G/L OF THE PATTERN.

AP = PATTERN PEAK AREA IN CHROMATOGRAM.

9.4.3. DETERMINATION: FILTER THE SAMPLE USING THE EQUIPMENT IN PARAGRAPH 9.2.1. AND INJECT A KNOWN QUANTITY INTO THE COLUMN.

9.5 CALCULATIONS.

THE CONTENT IN GLUCOSE AND FRUCTOSE, EXPRESSED IN G/L, IS OBTAINED BY THE FOLLOWING FORMULA:

GLUCOSE (G/L) = F 1 X TO 1 /4 F

FRUCTOSE (G/L) = F 2 X TO 2 /4 F

SIENIT:

F 1 = GLUCOSE RESPONSE FACTOR.

F 2 = FRUCTOSE RESPONSE FACTOR.

F = DILUTION FACTOR.

A 1 = GLUCOSE PEAK AREA IN THE SAMPLE.

A 2 = FRUCTOSE PEAK AREA IN THE SAMPLE.

9.6 REMARKS.

RESPONSE FACTORS MUST BE CALCULATED MULTIPLE TIMES DURING A SESSION. IT IS THEREFORE ADVISABLE TO HAVE THERMOSTAT THE DETECTOR.

10. TOTAL NITROGEN

10.1 PRINCIPLE.

DIGESTION OF THE PRODUCT WITH CONCENTRATED SULPHURIC ACID, IN THE PRESENCE OF A CATALYST, IN WHICH THE ORGANIC NITROGEN IS TRANSFORMED INTO AMMONIUM IONS, WHICH IN A STRONGLY BASIC MEDIUM, IS DISPLACED IN THE FORM OF AMMONIA, AND COLLECTED ON BORIC ACID. THE SUBSEQUENT EVALUATION WITH HYDROCHLORIC ACID ALLOWS THE CALCULATION OF THE INITIALLY PRESENT AMOUNT OF ORGANIC NITROGEN AND AMMONIACAL IN THE SAMPLE.

10.2 MATERIAL AND APARATOS.

10.2.1 KJELDAHL APPARATUS.

10.3 REAGENTS.

10.3.1 PURE SULPHURIC ACID, D = 1,84 G/ML.

10.3.2 SELENIUM CATALYST. MIX WELL WITH 80 G OF POTASSIUM SULPHATE, 20 G OF COPPER SULPHATE (II) AND 5 G OF SELENIUM.

10.3.3 PHENOLPHTHALEIN SOLUTION AND TORNASOL PAPER.

10.3.4 INDICATOR-WEIGH 105 MG OF METHYL RED AND 150 MG OF GREEN

BROMOCRESOL AND DISSOLVE 100 ML WITH ETHANOL.

10.3.5 BORIC ACID SOLUTION AT 1 PER 100. WEIGH 10 G OF BORIC ACID, DISSOLVE WITH WATER, ADD 10 ML OF THE INDICATOR (10.3.4) AND MAKE UP TO 1 LITRE WITH WATER.

10.3.6 SODIUM HYDROXIDE SOLUTION AT 40 PER 100.

10.3.7 HYDROCHLORIC ACID SOLUTION 0.05 N.

10.4 PROCEDURE.

PUT 5-10 ML OF GRAPE JUICE INTO THE KJELDAHL FLASK AND ADD 1 ML OF SULPHURIC ACID (10.3.1) TO EVAPORATE SLOWLY TO A SIRUPOSE CONSISTENCY. ADD 10 ML OF SULPHURIC ACID (10.3.1) AND 7 G OF CATALYST (10.3.2), CONTINUE TO HEAT FIRST SLOWLY AND THEN ENERGETICALLY UNTIL DISCOLOURATION, CONTINUE FOR A FEW MORE MINUTES. NEW DOSES OF SULPHURIC ACID (10.3.1) OF 5 IN 5 ML ARE ADDED IF NECESSARY.

COOL THE FLASK TO ROOM TEMPERATURE, ADD A FEW DROPS OF PHENOLPHTHALEIN AND TAKE IT TO THE DISTILLATION APPARATUS. IN A CYLINDRICAL GLASS OF ABOUT 200 ML ADD 25 ML OF BORIC ACID (10.3.5). ADD TO THE FLASK SODIUM HYDROXIDE SOLUTION (10.3.6) IN SUFFICIENT QUANTITY FOR THE USE OF FENOLPHTHALEIN. CONNECT THE DISTILLATION APPARATUS WITH THE WATER VAPOR GENERATOR AND START THE AMMONIA DRAG BY COLLECTING THE DISTILLATE IN THE BORIC ACID SOLUTION (10.3.5).

AFTER FIFTEEN-TWENTY MINUTES, CHECK WITH TORNASOL PAPER IF A DROP OF THE DISTILLATE DOES NOT ACCUSE ALKALINE REACTION. IN THIS CASE SEPARATE THE GLASS AND PROCEED TO THE VALUATION.

ASSESS WITH HYDROCHLORIC ACID 0.05 N (10.3.7).

10.5 CALCULATION.

THE NITROGEN CONTENT EXPRESSED IN MG/L SHALL BE GIVEN BY THE FOLLOWING FORMULA:

NITROGEN (MG/L) = 700 (V1-V0)/V

SIENIT:

V = VOLUME, IN ML, USED FOR SAMPLES.

V 1 = VOLUME, IN ML, OF HYDROCHLORIC ACID SOLUTION USED IN THE ASSESSMENT.

V 0 = VOLUME, IN ML, OF THE HYDROCHLORIC ACID SOLUTION USED IN THE TARGET.

10.6 REMARKS.

TO PERFORM THE KJELDAHL PROCEDURE, AUTOMATIC OR SEMI-AUTOMATIC SYSTEMS MAY BE USED, ADAPTING TO THE SPECIFICATIONS OF THE EQUIPMENT.

10.7 REFERENCES.

RÉÇEUIL DES MÉTHODES INTERNATIONALES D' ANALYSE DES VINS. O.I.V. A( 40).

1969.

11. ETHYL ALCOHOL

11.1 PRINCIPLE.

SEPARATION, IDENTIFICATION AND QUANTIFICATION OF ETHANOL, BY GASEOUS CHROMATOGRAPHY.

11.2 MATERIAL AND APARATOS.

11.2.1 GAS CHROMATOGRAPH EQUIPPED WITH FLAME IONIZATION DETECTOR.

11.2.2 CHROMATOGRAPHIC COLUMN. 2 M LENGTH COLUMN

AND 2 MM OF INTERNAL DIAMETER, PADDING OF PORAPAK Q 80-100 MESHES OR ANY OTHER COLUMN THAT ALLOWS THE SEPARATION AND QUANTIFICATION OF ETHANOL.

11.3 PROCEDURE.

11.3.1 CHROMATOGRAPHIC CONDITIONS: THE ORIENTATION CHROMATOGRAPHIC CONDITIONS FOR THE PORAPAK COLUMN ARE: NITROGEN CARRIER GAS 35 ML/MIN; OVEN TEMPERATURE 130 C; INJECTOR AND DETECTOR TEMPERATURE 180 C.

11.3.2 CALIBRATED.

11.3.2.1 INTERNAL PATTERN:

SOLUTION TO 10 PER 100 (V/V) OF PROPANOL-2 IN WATER.

11.3.2.2 PATTERN SOLUTION:

PREPARE AN ETHANOL-WATER SOLUTION CONTAINING THE PERCENTAGE OF ETHANOL THE SAMPLE IS SUPPOSED TO HAVE.

11.3.2.3 CALIBRATION SOLUTION: 100 ML OF THE STANDARD SOLUTION (11.3.2.2) IS ADDED 1 ML OF THE INTERNAL STANDARD SOLUTION (11.3.2.1) AND 1 MICROLITRE IS INJECTED INTO THE CHROMATOGRAPH.

11.3.2.4 SAMPLE PROBLEM: 100 ML OF THE SAMPLE ADD 1 ML OF THE INTERNAL STANDARD SOLUTION (11.3.2.1) AND INJECT 1 MICROLITRE INTO THE CHROMATOGRAPH.

11.4 CALCULATIONS.

CALCULATE THE RESPONSE FACTOR AND THE CONCENTRATION OF ETHYL ALCOHOL IN THE SAMPLE, USING THE FOLLOWING FORMULAS:

RESPONSE FACTOR (FR) = C1 X AP/AI

SAMPLE CONCENTRATION (% BY VOLUME) = FR X AIM/APM

SIENIT:

C I = PERCENTAGE BY VOLUME OF ETHYL ALCOHOL IN THE STANDARD SOLUTION.

A P = INTERNAL PATTERN AREA IN THE PATTERN SOLUTION.

A I = ETHYL ALCOHOL AREA IN THE STANDARD SOLUTION.

AIM = ETHYL ALCOHOL AREA IN THE TEST SAMPLE.

APM = INTERNAL PATTERN AREA IN THE PROBLEM SAMPLE.

11.5 REMARKS.

THE DETERMINATION OF ETHYL ALCOHOL SHALL BE MADE IMMEDIATELY AFTER THE OPENING OF THE PACKAGE.

12. FORMAL INDEX

12.1 PRINCIPLE.

ASSESSMENT OF THE ACIDITY OF THE COMPOUNDS FORMED BY THE REACTION OF FORMALDEHYDE WITH THE AMINO ACIDS.

12.2 MATERIAL AND APARATOS.

PH METRO.

12.3 REAGENTS.

12.3.1 SODIUM HYDROXIDE SOLUTION 0.25 N.

12.3.2 OXYGENATED WATER AT 30 PER 100.

12.3.3 FORMALDEHYDE SOLUTION. BRING THE PURE FORMALDEHYDE, FROM 35 PER 100 AT LEAST, TO PH 8.1 BY SOLUTION OF SODIUM HYDROXIDE (12.3.1), USING THE PH-METER. CHECK HOURLY.

12.4 PROCEDURE.

PUT 25 ML OF GRAPE JUICE INTO A BEAKER AND NEUTRALISE WITH SODIUM HYDROXIDE (12.3.1) UP TO PH 8.1, USING THE PH-METER. ADD 10 ML OF THE FORMALDEHYDE SOLUTION (12.3.3) AND MIX.

AT THE END OF ONE MINUTE PERFORM THE POTENTIOMETRIC ASSESSMENT OF THE SOLUTION PROBLEM WITH THE SODIUM HYDROXIDE SOLUTION (12.3.1) UP TO PH 8.1.

IF MORE THAN 20 ML OF THE SODIUM HYDROXIDE SOLUTION HAD BEEN USED, THE TITRATION SHOULD BE REDONE USING 15 ML OF FORMALDEHYDE SOLUTION INSTEAD OF 10 ML.

IF THE SAMPLE CONTAINS SULFUR DIOXIDE, ADD A FEW DROPS OF OXYGENATED WATER BEFORE NEUTRALIZATION.

12.5 EXPRESSION OF RESULTS.

THE FORMOL INDEX OF THE ANALYZED SAMPLE IS EQUAL TO THE AMOUNT OF ALKALINE SOLUTION USED IN THE ASSESSMENT, EXPRESSED IN ML OF 0.1 N SODIUM HYDROXIDE AND CORRESPONDING TO 100 ML OF GRAPE JUICE.

12.6 REFERENCES.

FÉDÉRATION INTERNATIONALE DES PRODUCTEURS DE JUS DE FRUITS. ANALYSIS F.I.P.J.F. NO. 30 YEAR 1984.

13. PROLINA

13.1 PRINCIPLE.

QUANTITATIVE DETERMINATION OF PROLINE BY REACTION WITH NINHYDRIN IN ACID MEDIUM.

13.2 MATERIAL AND APARATOS.

13.2.1 TEST TUBES WITH SCREW CAP.

13.2.2 SPECTROPHOTOMETER OR COLORIMETER THAT ALLOWS READINGS TO BE PERFORMED AT 517 NM.

13.2 REAGENTS.

13.3.1 NINHYDRIN AT 3 PER 100 IN ETHYLENE GLYCOL MONOMETHYL ETHER.

13.3.2 FORMIC ACID.

13.3.3 ISOPROPANOL-WATER 1: 1 (V/V).

13.4 PROCEDURE.

DILUTE THE SAMPLE UNTIL IT CONTAINS 5 TO 50 MG/L OF PROLINE. TAKE 0.5 ML OF DILUTED SAMPLE AND INTRODUCE IT INTO A TEST TUBE WITH A SCREW CAP, ADD 0.25 ML OF FORMIC ACID AND 1 ML OF NINHYDRIN SOLUTION TO 3 PER 100. HERMETICALLY CLOSE THE TUBE AND INTRODUCE IT INTO A BOILING WATER BATH FOR FOURTEEN OR FIFTEEN MINUTES. COOL IT TO ABOUT 20 C FROM FIVE TO TEN MINUTES, ADDING WHILE COOLING 5 ML ISOPROPANOL-WATER SOLUTION 1: 1 (V/V).

THEN PERFORM THE ABSORPTION READING AT 517 NM AFTER FIVE MINUTES AND BEFORE THIRTY MINUTES.

PERFORM A BLANK FOLLOWING THE PROCEDURE ABOVE, BUT USING 0.5 ML OF DISTILLED WATER INSTEAD OF THE PROBLEM SOLUTION.

13.5 INTERPRETATION OF RESULTS.

CALCULATE THE PROLINE CONTENT BY COMPARISON WITH A PATTERN CURVE COMPRISING CONCENTRATIONS BETWEEN 5 AND 50 MG/L.

13.6 REFERENCES.

C.S. DUGH J. OF FOOD SCIENCE 34 (1969). 228.

14. SORBICO ACID

14.1 PRINCIPLE.

SEPARATION AND QUANTIFICATION OF SORBIC ACID BY HIGH-EFFICIENCY LIQUID CHROMATOGRAPHY AND ULTRAVIOLET DETECTION

A 230 NM.

14.2 MATERIAL AND APARATOS.

14.2.1 SAMPLE AND SOLVENT FILTRATION EQUIPMENT TO REMOVE PARTICLES EXCEEDING 0,5 MM.

14.2.2 LIQUID CHROMATOGRAPH EQUIPPED WITH VARIABLE WAVELENGTH ULTRAVIOLET DETECTOR AND LOGGER.

14.2.3 COLUMN C-18 OF 250 X 4.6 MM OF 10 MM OR SIMILAR.

14.3 REAGENTS.

14.3.1 STANDARD SOLUTION OF 50 MG/L SORBIC ACID IN METHANOL.

14.3.2 PH PHOSPHATE BUFFER SOLUTION = 6.6. DISSOLVE 2.5 G OF HYDROGEN PHOSPHATE TRIHYDRATE (K 2 HPO 4 3/4 3H 2 O) AND 2.5 G OF POTASSIUM DIHYDROGEN PHOSPHATE (KH 2 PO 4) IN A WATER LITRO. FILTER THIS SOLUTION WITH (14.2.1).

14.3.3 METHANOL FOR HPLC.

14.4 PROCEDURE.

14.4.1 GUIDANCE CHROMATOGRAPHIC CONDITIONS:

MOBILE PHASE: METANOL-BUFFER PHOSPHATE 10:

90 (V/V).

FLOW: 1 ML/MIN.

14.4.2 CALIBRATION: INJECT 10 TO 20 ML OF THE STANDARD SOLUTION INTO THE CHROMATOGRAPH (14.3.1) AND CALCULATE THE RESPONSE FACTOR.

RESPONSE FACTOR (F) = CO/AP

SIENIT:

CO = CONCENTRATION IN MG/L SORBIC ACID.

AP = PEAK AREA IN THE PATTERN SOLUTION CHROMATOGRAM.

14.3.3 DETERMINATION:

PUT 10 ML OF GRAPE JUICE INTO A 50 ML FLASK AND MAKE UP TO THE MARK WITH METHANOL. HOMOGENIZE. FILTER WITH 14.2.1 AND INJECT BETWEEN 10 AND 20 ML IN THE CHROMATOGRAPH.

14.5 CALCULATIONS.

SORBIC ACID CONTENT EXPRESSED IN MG/L IS OBTAINED BY THE FOLLOWING FORMULA:

SORBICO ACID (MG/L) = F X TO 1 X F

SIENIT:

F = RESPONSE FACTOR.

A 1 = SORBIC ACID PEAK AREA IN THE SAMPLE.

F = SAMPLE DILUTION FACTOR.

14.6 REMARKS.

14.6.1 SENSITIVITY CAN BE INCREASED BY PERFORMING READS

A 250 NM.

14.7 REFERENCES.

T. STIJVE AND HISCHENHUBER-DEUTSCHE LEBENSMITTEL-RUNDSCHAU 80, JAHRG/HEFT 3/1984.

15. BENZOIC ACID

15.1 PRINCIPLE.

SEPARATION, IDENTIFICATION AND QUANTIFICATION OF BENZOIC ACID BY HIGH EFFICACY LIQUID CHROMATOGRAPHY AND DETECTION IN ULTRAVIOLET AT 230 NM.

15.2 MATERIAL AND APARATOS.

15.2.1 SAMPLE AND SOLVENT FILTRATION EQUIPMENT TO REMOVE PARTICLES ABOVE 0.5 MM.

15.2.2 LIQUID CHROMATOGRAPH EQUIPPED WITH VARIABLE WAVELENGTH ULTRAVIOLET DETECTOR AND LOGGER.

15.2.3 COLUMN C-18 OF 250 X 4.6 MM 10 MM OR SIMILAR.

15.3 REAGENTS.

15.3.1 BENZOIC ACID STANDARD SOLUTION IN METHANOL OF 50 MG/L.

15.3.2 PH PHOSPHATE BUFFER = 6.6. DISSOLVE 2.5 G OF HYDROGEN PHOSPHATE TRIHYDRATE (K 2 HPO 4 3/4 3H 2 O) AND 2.5 G OF POTASSIUM DIHYDROGEN PHOSPHATE (KH 2 PO 4) IN A WATER LITRO.

FILTER THIS SOLUTION WITH (15.2.1).

15.3.3 METHANOL FOR HPLC.

15.4 PROCEDURE.

15.4.1 GUIDANCE CHROMATOGRAPHIC CONDITIONS:

MOBILE PHASE:

METHANOL-TAMPON PHOSPHATE 10: 90 (V/V).

FLOW: 1 ML/MIN.

15.4.2 CALIBRATED:

INJECT IN THE CHROMATOGRAPH BETWEEN 10 AND 20 ML OF THE STANDARD SOLUTION (15.3.1) AND CALCULATE THE RESPONSE FACTOR.

RESPONSE FACTOR (F) = CO/AP

SIENIT:

CO = CONCENTRATION IN MG/L OF BENZOIC ACID.

AP = PEAK AREA IN THE PATTERN SOLUTION CHROMATOGRAM.

15.4.3 DETERMINATION: TAKE 10 ML OF JUICE IN A 50 ML FLASK AND MAKE UP TO THE MARK WITH METHANOL. FILTER AND INJECT FROM 10 TO 30 ML IN THE CHROMATOGRAPH.

15.5 CALCULATIONS.

BENZOIC ACID CONTENT EXPRESSED IN MG/L SHALL BE OBTAINED BY THE FOLLOWING FORMULA:

BENZOIC ACID (MG/L) = F X TO 1 X F

SIENIT:

F = RESPONSE FACTOR.

A 1 = AREA OF THE PEAK OF BENZOIC ACID IN THE SAMPLE.

F = SAMPLE DILUTION FACTOR.

15.6 REMARKS.

SENSITIVITY CAN BE INCREASED BY READING TO 217 NM.

15.7 REFERENCES.

T.

STIJVE AND C. HISCHENHUBER. DEUTSCHE LEBENSMITTEL-RUNDSCHAU/80, JAHRG/HEFT 3/1984.

16. HYDROXYMETHYLFURFURAL

16.1 PRINCIPLE.

SEPARATION, IDENTIFICATION AND QUANTIFICATION OF HYDROXYMETHYLFURFURAL BY HIGH EFFICACY LIQUID CHROMATOGRAPHY, AND ULTRAVIOLET DETECTION AT 285 NM.

16.2 MATERIAL AND APARATOS.

16.2.1 SAMPLE AND SOLVENT FILTRATION EQUIPMENT TO REMOVE PARTICLES ABOVE 0.5 MM.

16.2.2 LIQUID CHROMATOGRAPH EQUIPPED WITH VARIABLE WAVELENGTH ULTRAVIOLET DETECTOR AND LOGGER.

16.2.3 COLUMN C-18 OF 200 X 4.6 MM OF 5 MM OR SIMILAR.

16.3 REAGENTS.

PATTERN SOLUTION. 20 MG/L SOLUTION OF RECENTLY DISTILLED HYDROXYMETHYLFURFURAL IN METHANOL.

16.4 PROCEDURE.

16.4.1 GUIDANCE CHROMATOGRAPHIC CONDITIONS:

MOBILE PHASE: DISTILLED AND DEIONIZED WATER.

RETENTION TIME APPROX.:

7 MIN.

FLOW: 1 ML/MIN.

16.4.2 CALIBRATION: INJECT 20 ML OF THE STANDARD SOLUTION (16.3.1) INTO THE CHROMATOGRAPH AND CALCULATE THE RESPONSE FACTOR.

RESPONSE FACTOR (F) = CO/AP

SIENIT:

CO = CONCENTRATION, IN MG/L, OF HYDROXYMETHYLFURFURAL.

AP = PEAK AREA IN THE CHROMATOGRAM OF THE STANDARD SOLUTION.

16.4.3 DETERMINATION: INJECT 20 ML OF FILTERED SAMPLE INTO THE CHROMATOGRAPH.

16.5 CALCULATIONS.

THE HYDROXYMETHYLFURFURAL CONTENT EXPRESSED IN MG/L IS OBTAINED BY THE FOLLOWING FORMULA:

HYDROXYMETHYLFURFURAL (MG/L) = F X TO 1 X F

SIENIT:

F = RESPONSE FACTOR.

A 1 = HMF PEAK AREA IN THE SAMPLE.

F = SAMPLE DILUTION FACTOR.

17. ASHES

17.1 PRINCIPLE.

INCINERATION OF THE RESIDUE OBTAINED AFTER EVAPORATION OF THE GRAPE JUICE CARRIED OUT IN SUCH A WAY THAT ALL CATIONS (EXCEPT AMMONIUM) IN THE FORM OF CARBONATES AND OTHER ANHYDROUS MINERAL SALTS CAN BE OBTAINED.

17.2 MATERIAL AND APARATOS.

17.2.1 PLATINUM OR QUARTZ CAPSULE, ABOUT 80 MM IN DIAMETER, WITH FLAT BOTTOM.

17.2.2 WATER OF WATER AND ARENA.

17.2.3 ADJUSTABLE ELECTRIC OVEN.

17.2.4 ANALYTICAL SCALES WITH SENSITIVITY OF 0.1 MG.

17.3 PROCEDURE.

PUT 25 ML OF GRAPE JUICE INTO A TARADA CAPSULE. EVAPORATE WITH CAUTION IN WATER BATH (17.2.2) TO SIRUPOSE CONSISTENCY.

ADD A FEW DROPS OF OLIVE OIL TO THE RESIDUE, SLOWLY HEAT IN A SAND BATH (17.2.2), UNTIL MOST OF THE ORGANIC SUBSTANCE IS CHARRED. ENTER THE CAPSULE IN THE OVEN (17.2.3) TO 525 C UNTIL THE RESIDUE IS WHITE (USUALLY AT SIX OR EIGHT HOURS) (17.6.1).

IMMEDIATELY COOL THE CAPSULE IN A DESICCATOR (ABOUT THIRTY MINUTES) AND WEIGH QUICKLY.

SOMETIMES IT CAN HAPPEN THAT CARBON DOES NOT BURN COMPLETELY. IN THIS CASE, HUMIDIFY THE ASHES WITH DISTILLED WATER, EVAPORATE AGAIN AND CALCINED. IF IT WERE NECESSARY TO REPEAT THIS OPERATION SEVERAL TIMES.

17.4 CALCULATIONS.

THE CONTENT IN ASHES, EXPRESSED IN GRAMS PER LITRE, WILL BE GIVEN BY THE FOLLOWING FORMULA:

ASHES (G/L) = 40 X P

SIENIT:

P = WEIGHT IN G, OF THE ASHES CONTAINED IN 25 ML OF GRAPE JUICE.

17.5 REMARKS.

A SLIGHT REDDISH BROWN OF THE ASHES, POSSIBLY OF FAITH 2 OR 3 IS ACCEPTED AND DOES NOT REQUIRE FURTHER TREATMENT.

17.6 REFERENCES.

FEDERATION INTERNATIONAL DES PRODUCTEURS DE JUS DE FRUITS. METHOD N. 9. YEAR 1962.

18. MINERAL MATERIAL INSOLUBLE IN HYDROCHLORIC ACID AT 10 PER 100

18.1 PRINCIPLE.

TREATMENT OF ASHES WITH HYDROCHLORIC ACID AT 10 PER 100, UNDER THE CONDITIONS SPECIFIED IN THE METHOD.

18.2 MATERIAL AND APARATOS.

18.2.1 THE SAME AS IN (17.2).

18.2.2 FILTER PAPER, NO ASH, MEDIUM POROSITY OR FILTER CRUCIBLE NUMBER 3.

18.3 REAGENTS.

18.3.1 HYDROCHLORIC ACID (D = 1,19 G/ML) AND 38.32 PER 100 (P/P).

18.3.2 HYDROCHLORIC ACID SOLUTION AT 10 PER 100 (P/P).

18.3.3 100 G/L. SILVER NITRATE SOLUTION

18.4 PROCEDURE.

ADD TO THE TOTAL ASHES IN THE SAME CAPSULE THAT HAS BEEN USED FOR PREPARATION, FROM 15 TO 25 ML OF THE HYDROCHLORIC ACID SOLUTION (18.3.2).

CARRY THE CAPSULE AND KEEP IT BOILING FOR TEN MINUTES. COAT THE CAPSULE WITH A WATCH GLASS, TO PREVENT ANY PROJECTION.

ALLOW TO COOL AND FILTER THE CONTENTS OF THE CAPSULE THROUGH THE FILTER PAPER OR CRUCIBLE (18.2.2). WASH THE FILTER PAPER OR CRUCIBLE WITH WATER UNTIL THE WASHING WATERS ARE FREE OF HYDROCHLORIC ACID, WHICH IS CHECKED WITH THE SILVER NITRATE SOLUTION (18.3.3).

CAREFULLY EVAPORATE AND INCINERATE IN THE REGULATED OVEN TO 525 C FOR ONE TIME.

LEAVE TO COOL THE CAPSULE OR THE CRUCIBLE AND WEIGH WITH AN ACCURACY OF 0.001 G.

REPEAT INCINERATION OPERATIONS UNTIL THE MASS DIFFERENCE BETWEEN TWO SUCCESSIVE DETERMINATIONS IS LESS THAN 0,001 G.

18.5 CALCULATIONS.

THE ACID INSOLUBLE ASH CONTENT, EXPRESSED IN MG/L, SHALL BE GIVEN BY THE FOLLOWING EXPRESSION:

INSOLUBLE ASH MG/L = (P 1 P O) X 40

SIENIT:

P O = WEIGHT, IN MG, OF THE EMPTY CAPSULE OR THE EMPTY CRUCIBLE.

P 1 = WEIGHT, IN MG, OF THE CAPSULE OR CRUCIBLE WITH THE ACID-INSOLUBLE ASHES.

18.6 REFERENCES.

INSTITUTE FOR RATIONALIZATION AND STANDARDIZATION OF WORK, UNE 34-096-81.

19. TOTAL PHOSPHORUS

19.1 PRINCIPLE.

TRANSFORMATION OF THE PHOSPHORATED COMPOUNDS AND SUBSEQUENT SPECTROPHOTOMETRIC ASSESSMENT AS PHOSPHOMOLIBDOVANADATE.

19.2 MATERIAL AND APARATOS.

19.2.1 SPECTROPHOTOMETER OR COLORIMETER TO PERFORM READINGS AT 400 NM.

19.2.2 PLATINUM, QUARTZ OR SIMILAR CAPSULES.

19.3 REACTIVE.

19.3.1 PHOSPHATES PATTERN SOLUTION. DISSOLVE 0.2397 G OF POTASSIUM DIHYDROGEN PHOSPHATE (KH 2 PO 4), PREVIOUSLY DRIED IN STOVE FOR TWO HOURS AT 105 C, IN WATER AND TO MAKE UP TO 250 ML.

19.3.2 AMMONIUM MOLYBDATE SOLUTION. DISSOLVE 60 G OF AMMONIUM MOLYBDATE IN 900 ML OF HOT WATER, COOL AND MAKE UP TO ONE LITRE.

19.3.3 AMMONIUM METAVANADATE SOLUTION. DISSOLVE 1,5 G OF AMMONIUM METAVANADATE IN 690 ML OF HOT WATER, ADD 300 ML OF NITRIC ACID, COOL AND MAKE UP TO ONE LITRE.

19.3.4 METAMOLIBDOVANADATE SOLUTION. SLOWLY ADD THE AMMONIUM MOLYBDATE SOLUTION (19.3.2) ON THE AMMONIUM METAVANADATE SOLUTION (19.3.3), AGITATING. KEEP THE SOLUTION IN POLYETHYLENE BOTTLES.

19.3.5 HYDROCHLORIC ACID SOLUTION. (1 + 3) (V/V) IN WATER.

19.3.6 HYDROCHLORIC ACID SOLUTION. (1 + 9) (V/V) IN WATER.

19.4 PROCEDURE.

19.4.1 CALIBRATION CURVE. FROM THE PATTERN SOLUTION (19.3.1) PREPARE A SERIES OF SOLUTIONS CONTAINING 0.00; 0.005; 0.10; 0.15; 0.20; 0.25; 0.30; AND 0.35 MG OF P 2 OR 5 /10 ML RESPECTIVELY. THEN PUT UP TO 10 ML ALIQUOTS OF EACH SOLUTION IN GRADUATED FLASK

50 ML. QUICKLY ADD TO EACH FLASK 5 ML OF METAMOLIBDENOVANADATE REAGENT (19.3.4), MIX, MAKE UP AND CAP. LEAVE TO REST AT LEAST THIRTY MINUTES. PERFORM THE READINGS OF THE PATTERNS AGAINST THE SOLUTION 0.00 BEFORE AN HOUR, AT 400 NM. GRAPHICALLY REPRESENT CONCENTRATIONS AGAINST ABSORBED ABSORBANCES.

19.4.2 SAMPLE PREPARATION. TAKE 25 ML OF GRAPE JUICE AND OBTAIN THE ASHES ACCORDING TO OFFICIAL METHOD NUMBER 17. DISSOLVE THE ASHES IN 10 ML OF HYDROCHLORIC ACID SOLUTION (19.3.5) AND EVAPORATE IN A WATER BATH. DISSOLVE THE RESIDUE OBTAINED IN 10 ML OF HYDROCHLORIC ACID SOLUTION (19.3.6), HEAT IN BATH MARY AND TRANSFER TO FLASK OF 100 ML,

COOL AND MAKE UP WITH DISTILLED WATER.

SHAKE AND FILTER TO REMOVE THE INSOLUBLE MATERIALS PRESENT.

19.4.3 DETERMINATION. TAKE 10 ML OF THE FILTRATE AND CONTINUE AS IN THE CALIBRATION CURVE (19.4.1).

IF THE CONTENT OF P 2 OR 5 IN THE ASHES IS GREATER THAN 3.5 MG,

LEAD TO GRADUATED FLASK GREATER THAN 100 ML OR TO MAKE DILUTIONS UNTIL THE CONTENT OF P 2 5 IN THE ALIQUOT IS LESS THAN 0.35 MG.

19.5 CALCULATIONS.

THE CONTENT IN MG OF P 2 OR 5 IN 100 ML OF SAMPLE IS OBTAINED BY THE CALIBRATION CURVE, TAKING INTO ACCOUNT THE DILUTIONS MADE.

TO EXPRESS THE RESULT AS MG OF P IN 100 ML OF SAMPLE, TO FINE THE PREVIOUS RESULT BY 0,437.

19.6 REFERENCES.

OFFICIAL METHODS OF ANALYSIS OF THE AOAC, 14. EDITION, 1984.

20. SULFATOS

20.1 PRINCIPLE.

PRIOR TO THE REMOVAL OF THE SULFUR DIOXIDE BY BOILING, THE BARIUM CHLORIDE SULFATE IONS ARE PRECIPITATED, CALCINATED AND WEIGHED.

20.2 MATERIAL AND APARATOS.

20.2.1 FLASK ERLENMEYER 500 ML WITH 100 ML KEY AMPOULE AND STEAM RELEASE TUBE, BOTH OF WHICH ARE IN THE STOPPER. THE FLASK IS PLACED ON A 15 CM DIAMETER METAL DISC WITH A CIRCULAR OPENING OF 8 CM IN DIAMETER.

20.2.2 WATER BATH AND HOT PLATE.

20.3 REAGENTS.

20.3.1 2 N. HYDROCHLORIC ACID SOLUTION

20.3.2 BARIUM CHLORIDE SOLUTION. DISSOLVE 100 G OF BARIUM CHLORIDE DIHYDRATE (BACL 2 H 2 O) IN 100 ML OF WATER.

20.3.3 HYDROCHLORIC ACID D = 1.19 MG/L.

20.4 PROCEDURE.

20.4.1 REMOVAL OF SULFUR DIOXIDE FROM GRAPE JUICE. INSERT IN THE ERLENMEYER OF THE APPARATUS DESCRIBED 50 ML OF DISTILLED WATER AND 1 ML OF HYDROCHLORIC ACID (20.3.3).

BOIL THIS SOLUTION TO REMOVE AIR FROM THE APPLIANCE. INTRODUCE 100 ML OF GRAPE JUICE BY THE KEY AMPOULE, PREVENTING THE BOILING FROM STOPPING DURING THIS ADDITION. CONTINUE BOILING TO REDUCE THE VOLUME OF THE LIQUID TO ABOUT 100 ML BY ELIMINATING ALL 2

20.4.2 BARIUM SULFATE PRECIPITATION. CARRY THE RESIDUE FROM THE PREVIOUS EVAPORATION TO A GLASS OF 400 ML, RINSING THE FLASK WITH THE AMOUNT OF WATER SUFFICIENT TO BRING THE TOTAL VOLUME TO 200 ML. ADD 5 ML OF 2 N HYDROCHLORIC ACID AND BRING TO THE BOIL. ADD 10 ML OF BARIUM CHLORIDE SOLUTION DROP TO DROP, WITH THE PRECAUTION OF NOT STOPPING THE BOIL AND LEAVE TO REST IN WARM, PLACING THE GLASS ON PLATE AT 60 C FOR FOUR HOURS AND IN BOILING WATER BATH FOR TWO HOURS. IN THE CASE OF SMALL AMOUNTS OF PRECIPITATE, A SECOND COLD REST IS RECOMMENDED FOR TWELVE HOURS. FILTER BY FILTER WITHOUT ASHES, WASH THE GLASS AND PRECIPITATE WITH HOT WATER UNTIL NON-REACTION WITH SILVER NITRATE, CARRY THE CAREFULLY FOLDED FILTER TO CRUCIBLE OF TARADO PORCELAIN, DESICCATE, CALCINED AND AFTER COOLING IN A DESICCATOR, PESAR.

20.5 CALCULATION.

CALCULATE THE CONTENT OF SULPHATES EXPRESSED IN MEQ/L OR IN G/L OF POTASSIUM SULPHATE WITH AN APPROXIMATION OF +-0,05 G/L.

SULFATE = 85.68 P MEQ/L.

SULFATE = 7,465 P G/L POTASSIUM SULPHATE.

BEING P = WEIGHT OF THE ASHES IN G.

20.6 REFERENCES.

RÉÇEUIL DES MÉTHODES INTERNATIONALES D' ANALYSE DES VINS. O.I.V., A 14 (1969) 1-4.

21 (A). SULPHUR DIOXIDE

(PAUL METHOD)

21 (A) .1.

PRINCIPLE

SULFUR RELEASE BY ACIDIFICATION OF THE GRAPE JUICE, AIR STREAM ENTRAINMENT, BORBOTHEUS OXIDATION IN NEUTRAL OXYGENATED WATER, AND VALORIZATION OF THE FORMED SULPHURIC ACID. MODERATE BOILING RELEASE OF THE SULPHUROUS , WHICH IS LEFT IN THE GRAPE JUICE AFTER THE EXTRACTION OF THE SULPHUROUS AND ANALOGOUS TREATMENT AS IN THE DETERMINATION OF THE SULPHUROUS . THE SULFUROUS IS THE SUM OF THE SULFUROUS AND THE SULFUROUS . IT CAN BE DETERMINED BY ACIDIFYING THE GRAPE JUICE AND HEATING AND PROCEEDING AS IN THE PREVIOUS TWO CASES.

THIS METHOD IS APPLICABLE FOR SULPHUR DIOXIDE CONTENT EXCEEDING 10 MG/L.

21 (A) .2. MATERIAL AND APARATOS

USE THE APPARATUS REPRESENTED IN FIGURE 21 (A) .I.

21 (A) .2.1 MATRAZ OF 100 ML OR 250 ML.

21 (A) .2.2 BURBOTER TUBE PROVIDED WITH HOLLOW BALL AT ONE END WITH ABOUT 20 HOLES OF 0,2 MM IN DIAMETER AROUND THE MAXIMUM HORIZONTAL CIRCLE. 21 (A) .2.3 REFRIGERANT ACCORDING TO FIGURE 21 (A). I.

21 (A) .2.4 BOTTLE WITH WATER AND PLUG CROSSED BY THE TUBE THAT COMMUNICATES WITH THE BORER TO MAKE VACUUM, AND ANOTHER TUBE SUBMERGED IN WATER TO CHARGE THE INTENSITY OF THE VACUUM DUE TO THE DEPRESSION OF THE WATER COLUMN INSIDE THE WATER. TUBE, DEPRESSION TO BE MAINTAINED BETWEEN 20-30 CM.

21 (A) .2.5 WATER BATH ADJUSTABLE TO 10 C.

21 (A) .3. RACTIVE

21 (A) .3.1 FOSFORIC ACID AT 25 PER 100 (P/V).

21 (A) .3.2 OXYGENATED WATER OF 0.3 VOLUMES PER 100.

21 (A) .3.3 SODIUM HYDROXIDE N/100.

21 (A) .3.4 INDICATOR. MIX 100 MG OF METHYL RED, 50 MG OF METHYLENE BLUE AND 100 ML OF 50 ALCOHOL

21 (A) .4. PROCEDURE

21 (A) .4.1 FREE SULPHUR DIOXIDE ANALYSIS. IN THE 100 ML FLASK OF THE APPARATUS, PUT 10 ML OF GRAPE JUICE AND ADD 5 ML OF PHOSPHORIC ACID TO 25 PER 100, PLACING THE FLASK ON YOUR SITE. IF THE WEALTH IN SO 2 OF THE GRAPE JUICE IS SMALL, THE FLASK OF 250 ML IS USED AND 20-50 ML OF GRAPES ARE PUT.

IMMERSE THE FLASK IN A WATER BATH AT 10 C.

ADD 2-3 ML OF OXYGENATED WATER OF 0.3 VOLUMES AND TWO DROPS OF THE INDICATOR REAGENT IN THE FLASK B AND NEUTRALISE OXYGENATED WATER WITH NA (OH) N/100.

ADAPT THE FLASK B TO THE APPLIANCE AND MAKE CLEAR AIR (OR NITROGEN) FOR A DOCE-FIFTEEN MINUTES. REMOVE THE FLASK B AND ASSESS THE SULPHURIC ACID FORMED WITH SODA N/100 (21 (A) .3.3).

21 (A) .4.2 COMBINED SULPHUR DIOXIDE ANALYSIS. AFTER FINISHING THE VALUATION OF THE FREE SULPHUR DIOXIDE, PLACE IN THE FLASK B, ALREADY CLEAN, THE 2-3 ML. NEUTRALIZED OXYGENATED WATER AND THE TWO DROPS OF THE INDICATOR. HEAT WITH SMALL FLAME TO BRING TO THE BOIL THE GRAPE JUICE LEFT IN THE FLASK AFTER THE PREVIOUS DETERMINATION.

APPLY THE DIRECT FIRE ON THE BOTTOM OF THE FLASK, WHICH WILL REST ON PERFORATED METAL SHEET WITH A HOLE OF 30 MM IN DIAMETER, TO PREVENT THE PYROGENATION OF THE SUGARS FROM THE GRAPE JUICE ON THE WALLS OF THE FLASK.

MAINTAIN THE PASSAGE OF AIR OR NITROGEN DURING THE BOILING PERIOD LASTING ONE-FIFTHS OF A MINUTE, WHICH IS CONSIDERED SUFFICIENT TO DRAG ALL THE COMBINED SULPHUROUS AND THEN OXIDIZE IT. REMOVE THE FLASK B AND ASSESS THE SULPHURIC ACID FORMED WITH SODA N/100 (21 (A) .3.3).

21 (A) .4.3 TOTAL SULPHUR DIOXIDE. IT CAN BE DETERMINED BY THE SUM OF FREE SULPHUR DIOXIDE PLUS THE COMBINED SULPHUR DIOXIDE, BUT IT CAN ALSO BE DETERMINED DIRECTLY, ACTING FROM A START WITH AIR OR NITROGEN CURRENT AND WITH HEAT.

21 (A) .5 CALCULATIONS

CALCULATE THE SULPHUR DIOXIDE CONTENT EXPRESSED IN MG/L, WITH AN APPROXIMATION OF 10 MG/L.

SULPHUR DIOXIDE = 320V1/V2 MG/L

SIENIT:

V 1 = VOLUME, IN ML, OF NAOH N/100, SPENT ON VALUATION.

V 2 = VOLUME, IN ML, SAMPLE FOR ANALYSIS.

21 (A) .6. REFERENCES

21 (A) .6.1 PAUL, F.

, A: 8, 21, 1958.

21 (A) .6.2 IL DES METHODS INTERNATIONALES D' ANALYSE DES VINS, O.I.V., A17, 1-8, 1969.

22. POTASSIUM

22.1 PRINCIPLE

POTASSIUM IS DETERMINED BY FLAME PHOTOMETRY AFTER ADDITION OF LITHIUM CHLORIDE, TO PREVENT PARTIAL IONIZATION OF THE METALS IN THE FLAME.

22.2 MATERIAL AND APARATOS

22.2.1 ATOMIC ABSORPTION SPECTROPHOTOMETER.

22.2.2 NORMAL LABORATORY USE MATERIAL.

22.3 REAGENTS

22.3.1 POTASSIUM SOLUTION OF 1,000 MG/L.: DISSOLVE 1,907 G OF POTASSIUM CHLORIDE (KCL) IN A LITRE OF DISTILLED WATER.

22.3.2 LITHIUM CHLORIDE SOLUTION: DISSOLVE 37.3 G OF LITHIUM CHLORIDE (LICL) IN 100 ML OF DISTILLED WATER.

23.3.3 POTASSIUM SOLUTIONS OF 0, 1, 2, 3, 5, 7 MG/L PREPARED FROM (22.3.1), AFTER ADDITION OF THE REQUIRED AMOUNT OF LITHIUM CHLORIDE, FOR LITHIUM TO BE FOUND IN A RATIO OF APPROXIMATELY 2,000 MG/L.

22.4 PROCEDURE

TAKE 1 ML OF SAMPLE AND BRING TO 200 ML WITH DISTILLED WATER (AFTER ADDITION OF THE REQUIRED AMOUNT OF LITHIUM CHLORIDE FOR LITHIUM TO BE IN A PROPORTION OF ABOUT 2,000 MG/L).

READING IN FLAME PHOTOMETRY VERSUS REFERENCE SOLUTIONS AT 766-770 NM.

22.5 CALCULATIONS

THE POTASSIUM CONTENT IS CALCULATED FROM THE VALUE OBTAINED IN THE SPECTROPHOTOMETER BY COMPARISON WITH THE PATTERN CURVE, TAKING INTO ACCOUNT THE DILUTION PERFORMED. THE RESULTS ARE EXPRESSED IN MG POTASIO/100 ML SAMPLE.

22.6 REMARKS

A 40 G/L SOLUTION OF CESIUM CHLORIDE CAN BE USED INSTEAD OF LITHIUM CHLORIDE, IN THIS CASE THE APPROPRIATE CONCENTRATION OF CESIUM CHLORIDE IN THE DISSOLUTIONS OF THE SAMPLES AND PATTERNS BETWEEN 0.1-0.4 PER 100.

22.7 REFERENCES

22.7.1 FEDERATION INTERNATIONAL DES PRODUCTEURS DE JUS DE FRUITS. METHOD NUMBER 33. YEAR 1984.

22.7.2 METHODS ASSOCIATION OF OFFICIAL ANALYTICAL CHEMISTS. ED.

1984.

23. SODIO

23.1 PRINCIPLE

SODIUM IS DETERMINED BY FLAME PHOTOMETRY AFTER ADDITION OF LITHIUM CHLORIDE, TO PREVENT PARTIAL IONIZATION OF THE METALS IN THE FLAME.

23.2 MATERIAL AND APARATOS

23.2.1 ATOMIC ABSORPTION SPECTROPHOTOMETER OR FLAME PHOTOMETER.

23.2.2 NORMAL LABORATORY USE MATERIAL.

23.3 REAGENTS

23.3.1 1,000 MG/L SODIUM SOLUTION: DISSOLVE 2,542 G OF SODIUM CHLORIDE (NACL) IN A LITER OF DISTILLED WATER.

23.3.2 LITHIUM CHLORIDE SOLUTION: DISSOLVE 37.3 G OF LITHIUM CHLORIDE (LICL) IN 100 ML OF DISTILLED WATER.

23.3.3 SODIUM SOLUTIONS OF 0, 1, 2, 3 AND 5 MG/L PREPARED FROM (23.3.1), AFTER ADDITION OF THE REQUIRED AMOUNT OF LITHIUM CHLORIDE, FOR LITHIUM TO BE FOUND IN A PROPORTION OF APPROXIMATELY 2,000 MG/L.

23.4 PROCEDURE

TAKE 1 ML OF SAMPLE AND LEAD TO 100 ML (SEE 23.6.2) WITH DISTILLED WATER (AFTER ADDITION OF THE REQUIRED AMOUNT OF LITHIUM CHLORIDE FOR LITHIUM TO BE IN A PROPORTION OF ABOUT 2,000 MG/L), READ IN FLAME PHOTOMETRY IN FRONT OF THE REFERENCE SOLUTIONS AT 589 NM.

23.5 CALCULATIONS

THE SODIUM CONTENT IS CALCULATED FROM THE VALUE OBTAINED BY COMPARISON WITH THE STANDARD CURVE, TAKING INTO ACCOUNT THE DILUTION TAKEN. THE RESULTS ARE EXPRESSED IN MG OF SAMPLE SODI/L.

23.6 REMARKS

23.6.1 A 40 G/L SOLUTION OF CESIUM CHLORIDE IN PLACE OF LITHIUM CHLORIDE CAN BE USED, IN THIS CASE THE APPROPRIATE CONCENTRATION OF CESIUM CHLORIDE IN THE DISSOLUTIONS OF THE SAMPLES AND PATTERNS BETWEEN 0.1 AND 0.4 PER 100.

23.6.2 PERFORM THE NECESSARY DILUTIONS SO THAT THE SAMPLE IS IN THE RANGE OF THE CURVE.

23.7 REFERENCES

23.7.1 FEDERATION INTERNATIONAL DEL PRODECTEURS DE JUS DE FRUITS.

METHOD NUMBER 33. YEAR 1984.

23.7.2 METHODS ASSOCIATION OF OFFICIAL ANALYTICAL CHEMISTS. ED. 1984.

24. ARSENIC

24.1 PRINCIPLE

THE SAMPLE IS SUBJECTED TO ACID DIGESTION WITH A MIXTURE OF NITRIC AND SULPHURIC ACID.

ARSENIC DETERMINATION IS PERFORMED BY ATOMIC ABSORPTION SPECTROPHOTOMETRY, WITH HYDRIDE GENERATOR.

24.2 MATERIAL AND APARATOS

24.2.1 MATARIAL OF NORNAL USE IN LABORATORY.

24.2.2 MATCHES KJELDAHL 250 ML.

24.2.3 ATOMIC ABSORPTION SPECTROPHOTOMETER EQUIPPED WITH HYDRIDE GENERATOR SYSTEM.

24.2.4 ELECTROLESS DISCHARGE LAMP.

24.2.5 POWER SOURCE FOR ELECTROLESS DISCHARGE LAMP.

24.3 REAGENTS

24.3.1 HYDROCHLORIC ACID (D = 1,19 G/ML).

24.3.2 DISSOLUTION OF HYDROCHLORIC ACID 32 PER 100 V/V: DILUTE 32 ML OF HYDROCHLORIC ACID (D = 1,19 G/ML) WITH DISTILLED WATER UP TO A VOLUME OF 100 ML.

24.3.3 DISSOLUTION OF HYDROCHLORIC ACID 1.5 PER 100 V/V: DILUTE 15 ML OF HYDROCHLORIC ACID (D = 1,19 G/ML) WITH DISTILLED WATER UP TO A VOLUME OF 1,000 ML.

24.3.4 NITRIC ACID (D = 1.40 G/ML).

24.3.5 SULFURIC ACID (D = 1.84 G/ML).

24.3.6 DISSOLUTION OF SODIUM HYDROXIDE AT 1 PER 100 (P/V):

WEIGH 1 G OF SODIUM HYDROXIDE AND DISSOLVE IT WITH DISTILLED WATER UP TO A VOLUME OF 100 ML.

24.3.7 DISSOLUTION OF SODIUM BOROHYDRIDE AT 3 PER 100 (P/V):

WEIGH 3 G SODIUM BOROHYDRIDE AND DISSOLVE IT UP TO 100 ML

WITH SODIUM HYDROXIDE AT 1 PER 100 (24.3.6).

24.3.8 DISSOLUTION OF TRITIPLEX III TO 1 PER 100 (W/V): WEIGH 1 G OF TRITIPLEX III AND DISSOLVE IT UP TO 100 ML WITH DISTILLED WATER.

24.3.9 DISSOLUTION OF POTASSIUM HYDROXIDE AT 20 PER 100 (P/V):

WEIGH 20 G OF POTASSIUM HYDROXIDE AND DISSOLVE IT WITH DISTILLED WATER UP TO A VOLUME OF 100 ML.

24.3.10 DISSOLUTION OF SULPHURIC ACID AT 20 PER 100 (V/V): DILUTE 20 ML OF SULPHURIC ACID (24.3.5) WITH DISTILLED WATER UP TO A VOLUME OF 100 ML.

24.3.11 DISSOLUTION OF SULPHURIC ACID AT 1 PER 100 (V/V): DILUTE 1 ML OF SULPHURIC ACID (24.3.5) WITH DISTILLED WATER UP TO A VOLUME OF 100 ML.

24.3.12 CONCENTRATION ARSENIC PATTERN 1 G/L:

DISSOLVE 0.132 G OF ARSENIC TRIOXIDE IN 2.5 ML OF POTASSIUM HYDROXIDE AT 20 PER 100 (24.3.9), NEUTRALISE WITH SULPHURIC ACID AT 20 PER 100 (24.3.10), DILUTE UP TO 100 ML WITH SULPHURIC ACID 1 PER 100 (24.3.11).

24.3.13 CONCENTRATION ARSENIC PATTERN 10 MG/L:

PIPETAR 1 ML OF THE ARSENIC PATTERN SOLUTION (24.3.12) IN A 100 ML VOLUMETRIC FLASK. DILUTE TO THE ROOT WITH DISTILLED WATER.

24.3.14 0.1 MG/L CONCENTRATION ARSENIC PATTERN SOLUTION:

PIPETAR 1 ML OF ARSENIC SOLUTION (24.3.13) IN A 100 ML VOLUMETRIC FLASK. DILUTE TO THE ROOT WITH DISTILLED WATER.

24.4 PROCEDURE

24.4.1 SAMPLE PREPARATION: IN A 250 ML FLASK KJELDAHL, ENTER 2 G OF SAMPLE WITH 20 ML OF NITRIC ACID (24.3.4)

AND 5 ML SULFURIC ACID (24.3.5).

BRING TO A BOIL UP TO APPROXIMATELY 5 ML.

ALLOW TO COOL AND DISSOLVE WITH DISTILLED WATER IN A 50 ML FLASK OF THE RESULTING SOLUTION.

24.4.2 PREPARATION OF WORKING PATTERNS AND WHITE: IN A KJELDAHL FLASK ENTER 5 ML OF THE ARSENIC SOLUTION (24.3.14) AND SUBJECT TO THE SAME TREATMENT AS THE SAMPLE, 1 ML OF THE SOLUTION CONTAINS 10 NANOGRAMS OF ARSENIC.

PREPARE A TARGET WITH ALL THE REAGENTS USED FOLLOWING THE TREATMENT GIVEN TO THE SAMPLE.

24.4.3 CONDITIONS OF THE SPECTROPHOTOMETER: TURN ON THE POWER SUPPLY OF THE DISCHARGE LAMPS WITHOUT ELECTRODES IN SUFFICIENT TIME TO STABILIZE THE ENERGY OF THE LAMP.

TURN ON THE SPECTROPHOTOMETER, ADJUST THE WAVELENGTH TO 193.7 NM, PLACING THE GRID ACCORDING TO THE CONDITIONS OF THE APPARATUS.

TURN ON THE HYDRIDE GENERATOR, ADJUSTING THE CELL TEMPERATURE TO 900 C, WAITING UNTIL THAT TEMPERATURE IS REACHED.

THE CONDITIONS OF THE HYDRIDE GENERATOR ARE ADJUSTED ACCORDING TO THE SPECIFICATIONS OF THE APPARATUS.

ADJUST THE ARGON FLOW ACCORDING TO THE CHARACTERISTICS OF THE APPARATUS.

24.4.4 DETERMINATION: ARSENIC CONCENTRATION DETERMINATIONS ARE MADE BY THE METHOD OF ADDING PATTERNS BY MEANS OF DUPLICATE MEASURES IN THE MIRROR UNDER THE SPECIFIED CONDITIONS (24.4.3), ADDING TO THE SOLUTION 3 ML REACTION FLASK (24.3.8). AS INTERNAL PATTERNS, 10, 20, AND 50 NG OF ARSENIC ARE USED.

WASH FLASKS BEFORE AND AFTER EACH USE WITH HYDROCHLORIC ACID 1.5 PER 100 (24.3.3).

BY CONSTRUCTING THE ADDITION CHART, YOU HAVE TO DISCOUNT THE ABSORBENCY VALUE OF THE TARGET OBTAINED UNDER THE SAME CONDITIONS ABOVE, BUT ADD 3 ML OF THE WHITE SOLUTION.

IN THESE CONDITIONS, THE LIMIT OF DETECTION OF THE TECHNIQUE IS 5 NG.

25. IRON

25.1 PRINCIPLE.

DETERMINATION OF IRON BY ATOMIC ABSORPTION PRIOR MINERALIZATION OF THE SAMPLE.

25.2 MATERIAL AND APARATOS.

25.2.1 ATOMIC ABSORPTION SPECTROPHOTOMETER.

25.2.2 IRON LAMP.

25.2.3 USED FOR LEAD IN (26.2.3), (26.2.4) AND (26.2.5).

25.3 REAGENTS.

25.3.1 USED FOR LEAD IN (26.3.1), (26.3.2) AND (26.3.4).

25.3.2 IRON PATTERN SOLUTION. DISSOLVE 1 GRAM OF AMMONIUM SULPHATE AND IRON (III) DODECAHYDRATE (NH 4 FE (SO 4) 2. 12 H 2 O) IN 50 ML OF THE NITRIC ACID SOLUTION (1 + 1) AND DILUTE UP TO 1,000 ML WITH 1 PER 100 NITRIC ACID (V/V).

25.4 PROCEDURE.

25.4.1 PREPARATION OF THE SAMPLE. AS IN (26.4.1).

25.4.2 CALIBRATION CURVE. FROM THE PATTERN SOLUTION (25.3.2), PREPARE A SERIES OF SOLUTIONS CONTAINING 0.5 TO 5.0 MG OF IRON PER LITRE, WITH NITRIC ACID AT 1 PER 100 (V/V).

25.4.3 DETERMINATION.

SAME AS FOR LEAD. PERFORM THE READINGS AT 248.3 NM.

25.5 CALCULATIONS.

OBTAIN THE IRON CONTENT OF THE SAMPLE BY INTERPOLATION FROM THE CALIBRATION CURVE AND TAKING INTO ACCOUNT THE DILUTIONS MADE.

26. Lead

26.1 PRINCIPLE.

DETERMINATION OF LEAD BY ATOMIC ABSORPTION AFTER SAMPLE MINERALIZATION.

26.2 MATERIAL AND APARATOS.

26.2.1 ATOMIC ABSORPTION SPECTROPHOTOMETER.

26.2.2 LEAD LAMP.

26.2.3 PLATINUM, QUARTZ OR SIMILAR CAPSULES.

26.2.4 SAND BATH OR HEATING PLATE.

26.2.5 ELECTRIC OVEN (MUFLA) WITH TEMPERATURE CONTROL DEVICE.

26.3 REAGENTS.

26.3.1 NITRIC ACID 70 PER 100 (D = 1,4135).

26.3.2 NITRIC ACID AT 1 PER 100 IN DISTILLED WATER (V/V) OF (26.3.1).

26.3.3 STANDARD SOLUTION OF 1,000 MG OF PB/1. Dissolve 1.598 G

DE (NO 3) 2 PB SCRAPING 1,000 ML WITH NITRIC ACID AT 1 PER 100.

26.3.4 SULPHURIC ACID OF 96 PER 100 (D = 1,835).

26.4 PROCEDURE.

26.4.1 PREPARATION OF THE SAMPLE. PLACE 100 ML OF THE SAMPLE IN A CAPSULE (26.2.3) AND BRING IT TO EVAPORATION TO SIRUPOSE CONSISTENCY IN A SAND BATH. ADD 2 ML OF SULPHURIC ACID AND CARBONISE THE RESIDUE IN THE SAND BATH. THEN, INSERT THE CAPSULE INTO THE MUFLA AND KEEP IT FOR HOURS AT 450 C, AFTER THAT TIME, REMOVE IT AND LET IT COOL. ADD 1 ML OF CONCENTRATED NITRIC ACID, EVAPORATE IN THE SAND BATH AND ENTER THE MUFLA, REPEATING UNTIL WHITE ASHES ARE OBTAINED. A SLIGHT REDDISH BROWN COLOR IN THESE, POSSIBLY OF FAITH 2 OR 3 IS ACCEPTED AND DOES NOT REQUIRE FURTHER TREATMENT. THEN DISSOLVE THE ASHES WITH 1 ML OF CONCENTRATED NITRIC ACID AND 2 ML OF DISTILLED WATER, ONCE DISSOLVED FILTER AND COLLECT THE FILTRATE IN A 10 ML FLASK, WASHING THE CAPSULE AND FILTER WITH DISTILLED WATER TO THE ROOT.

26.4.2 PATTERN CURVE. DILUTE APPROPRIATE ALIQUOTS OF THE STANDARD SOLUTION (26.3.3) WITH NITRIC ACID (26.3.2) TO OBTAIN A CONCENTRATION CURVE 2, 4, 6, 8 AND 10 MG/L.

26.4.3 DETERMINATION. OPERATE ACCORDING TO THE SPECIFICATIONS OF THE APPARATUS; USING AIR-ACETYLENE FLAME. MEASURE THE ABSORBANCES OF THE SAMPLE AND PATTERNS AT 283 NM. IF THE SOLUTION IS VERY CONCENTRATED, DILUTE IT WITH NITRIC ACID AT 1 PER 100.

26.5 CALCULATIONS.

CALCULATE THE LEAD CONTENT, EXPRESSED IN MG/L BY COMPARISON WITH THE CORRESPONDING STANDARD CURVE AND TAKING INTO ACCOUNT THE DILUTION FACTOR.

26.6 REFERENCES.

OFFICIAL WINE ANALYSIS METHODS. MINISTRY OF AGRICULTURE, PAGE 134 (I), 1976.

27. THIS

27.1 PRINCIPLE.

DETERMINATION OF TIN BY ATOMIC ABSORPTION, AFTER ACID DIGESTION.

27.2 MATERIALS AND APARATOS.

27.2.1 ATOMIC ABSORPTION SPECTROPHOTOMETER.

27.2.2 TIN LAMP.

27.2.3 NORMAL USE MATERIAL IN LABORATORIES.

27.3 REAGENTS.

27.3.1 CONCENTRATED HYDROCHLORIC ACID.

27.3.2 HYDROCHLORIC ACID 7 N.

27.3.3 WATER DESIONIZADA.

27.3.4 STANDARD SOLUTION OF 1,000 MG/L TIN. DISSOLVE 1,000 G. OF TIN METAL IN 100 ML OF CONCENTRATED HYDROCHLORIC ACID AND DILUTE UP TO 1,000 ML WITH DEIONISED WATER.

27.4 PROCEDURE.

27.4.1 SAMPLE PREPARATION:

MEASURE 1 TO 5 ML OF THE SAMPLE DIRECTLY IN AN ERLENMEYER. ADD 25 ML HYDROCHLORIC ACID SOLUTION CL H 7 N. BRING TO THE BOIL AND KEEP IT ON FIRE LENTRO FOR FIVE MINUTES. COOL AND QUANTITATIVELY TRANSFER TO A 50 ML FLASK, MAKING UP WITH DISTILLED WATER. SHAKE AND FILTER WITH WATMAN PAPER NUMBER 1.

27.4.2 CALIBRATION CURVE: FROM SOLUTION (27.3.4), PREPARE A SERIES OF SOLUTIONS CONTAINING 50, 100, 150 AND 250 MG/L OF TIN.

27.4.3 DETERMINATION: OPERATE ACCORDING TO THE SPECIFICATIONS OF THE APPARATUS USING A NITROSO-ACETYLENE OXIDE REDUCING FLAME.

MEASURE THE ABSORBANCES OF THE SAMPLE AND PATTERNS TO 286 NM.

27.5 CALCULATIONS.

OBTAIN THE TIN CONTENT OF THE SAMPLE BY INTERPOLATION FROM THE CALIBRATION CURVE.

28. COBRE

28.1 PRINCIPLE.

DETERMINATION OF COPPER BY ATOMIC ABSORPTION, AFTER MINERALIZATION OF THE SAMPLE.

28.2 MATERIAL AND APARATOS.

28.2.1 ATOMIC ABSORPTION SPECTROPHOTOMETER.

28.2.2 COPPER LAMP.

28.2.3 USED FOR LEAD IN (26.2.3), (26.2.4) Y (26.2.5).

28.3 REAGENTS.

28.3.1 USED FOR LEAD IN (26.3.1), (26.3.2) AND (26.3.4).

28.3.2 STANDARD SOLUTION OF 1,000 MG OF CU/L. DISSOLVE 1,000 G OF PURE CU IN THE REQUIRED MINIMUM VOLUME OF NOT 3 H (1: 1) AND DILUTE TO ONE LITRE WITH NITRIC ACID 1 PER 100 (V/V).

28.4 PROCEDURE.

28.4.1 PREPARATION OF THE SAMPLE. AS IN (26.4.1).

28.4.2 PATTERN CURVE CONSTRUCTION. DILUTE ALIQUOT PARTS OF THE STANDARD SOLUTION (28.3.2) WITH 1 PER 100 NITRIC ACID TO OBTAIN SOLUTIONS CONTAINING 1 TO 5 MG COPPER.

28.4.3 DETERMINATION. SAME AS FOR LEAD. MEDIR AT 324.7 NM.

28.5 CALCULATIONS.

BASED ON THE ABSORBANCE VALUES OBTAINED FOR THE SAMPLE, THE COPPER CONCENTRATIONS OF THE SAMPLE ARE FOUND BY THE PATTERN CURVE, TAKING INTO ACCOUNT THE DILUTION FACTOR.

29. CNC

29.1 PRINCIPLE.

DETERMINATION OF ZINC BY ATOMIC ABSORPTION, AFTER MINERALIZATION OF THE SAMPLE.

29.2 MATERIAL AND APARATOS.

29.2.1 ATOMIC ABSORPTION SPECTROPHOTOMETER.

29.2.2 LAMP OF CCN.

29.2.3 USED FOR PB IN (26.2.3), (26.2.4) AND (26.2.5.).

29.3 REAGENTS.

29.3.1 USED FOR LEAD IN (26.3.1), (26.3.2) AND (26.3.4).

29.3.2 1.000 MG/L. ZINC PATTERN SOLUTION DISSOLVE 1,000 G OF ZN, BUT IN THE MINIMUM REQUIRED VOLUME OF NITRIC ACID (1: 1) AND DILUTE TO ONE LITRE WITH NITRIC ACID 1 PER 100 (V/V).

29.4 PROCEDURE.

29.4.1 SAMPLE PREPARATION. AS IN (26.4.1).

29.4.2 PATTERN CURVE CONSTRUCTION. DILUTE ALIQUOT PARTS OF THE STANDARD SOLUTION (29.3.2) WITH NITRIC ACID TO 1 PER 100 FOR SOLUTIONS OF 0.5 TO 1 MG/L.

29.4.3 DETERMINATION: SAME AS FOR LEAD.

THE READING WILL BE DONE AT 213.5 NM.

29.5 CALCULATIONS.

BASED ON THE OBTAINED ABSORBENCY VALUES, FIND THE ZN CONCENTRATIONS FOR THE SAMPLE, TAKING INTO ACCOUNT THE CONCENTRATION OR DILUTION FACTOR.