Amendment Of The Decree On Sampling And Chemical Analysis Of Samples Of Fertilizers

Original Language Title: změna vyhlášky o odběrech a chemických rozborech vzorků hnojiv

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Read the untranslated law here: https://portal.gov.cz/app/zakony/download?idBiblio=49992&nr=475~2F2000~20Sb.&ft=txt

475/2000 Coll.
DECREE

Ministry of Agriculture


Dated 13 December 2000

Amending Ministry of Agriculture Decree no. 273/1998 Coll., On
sampling and chemical analysis of samples of fertilizers

The Ministry of Agriculture stipulates pursuant to § 16 point. b) Act no. 156/1998
Coll., on fertilizers, auxiliary soil substances, auxiliary plant
preparations and substrates and on agrochemical testing of agricultural land
(Fertilizers Act), as amended by Law no. 308 / 2000 Sb .:
Article I


Decree no. 273/1998 Coll., On sampling and chemical analysis of samples
fertilizers, is amended as follows:

First In § 9. 3, "which they are reproducible and have the highest detection rate
microorganisms" is replaced by "listed in Annex
no. 3".

Second Annex no. 2 reads:

"Příl.2

Methods of chemical analyzes

first

Preparing samples for analysis

Editing final sample delivered to the laboratory is a sequence of operations,
most sieving, grinding and homogenization being conducted
so

a) the smallest test sample, the expected analytical methods were
representative for the final sample

b) the treatment of grain, fertilizer was not changed so much that it would
significantly affect its solubility in various extracting agents.

second



Nitrogen 2.1 Determination of ammonium

nitrogen 2.1.1 Determination of ammonia nitrogen by distillation method

Ammonia is displaced with excess sodium hydroxide and distilled
bound in a known volume of standard sulfuric acid, the excess of which is determined
titration with standard sodium hydroxide solution.

2.1.2 Determination of ammonia nitrogen by formaldehyde method

ammonium ions in aqueous solution by reaction with formaldehyde converted into
practically neutral hexamethylenetetramine, whereby releasing || | equivalent quantity of oxonium ions. They are directly determined by titration
standard sodium hydroxide solution to phenolphthalein.

02.02 Determination of ammonium and nitrate nitrogen according to Devarda

Nitrates and potentially present nitrites in strongly alkaline environments
reduce nascent hydrogen produced by reaction Devarda
alloy with sodium hydroxide. The ammonia produced together with that originally present
distilled and bound in a known volume of standard
sulfuric acid, the excess of which is determined by titration with a standard solution of sodium hydroxide
.

03.02 Determination of total nitrogen (sum of inorganically and organically bound nitrogen
)

2.3.1 Determination of total nitrogen in nitrogenous lime without nitrates

Sample is decomposed by Kjeldahl method by boiling with sulfuric acid in the presence of a copper catalyst
. From the resulting ammonium sulfate
ammonia is displaced with sodium hydroxide and distilled into a known volume
standard sulfuric acid, the excess of which is determined by titration
standard sodium hydroxide solution.

2.3.2 Determination of total nitrogen in lime with nitrates

First, metallic iron (powder) and stannous chloride are reduced
nitrates to ammonia and the sample is decomposed by the Kjeldahl method as in paragraph
. 2.3.1.

2.3.3 Determination of total nitrogen in urea

Nitrogen from urea is boiling the sample with sulfuric acid is converted to ammonium
from alkaline environment distilled into a known volume of volumetric
solution of sulfuric acid and the excess is determined by titration with volumetric
sodium hydroxide solution.

04.02 Determination of cyanamide nitrogen

Cyanamide is precipitated from the solution as a silver salt which is decomposed
Kjeldahl method and nitrogen is determined as in. 2.3.1.

05.02 Determination of biuret in urea

Biuret forms in the alkaline medium in the presence of tartrate, sodium tartrate
with bivalent copper violet soluble complex
whose absorbance is measured at a wavelength of 546 nm.

06.02 Determination of different forms of nitrogen

Determination of different forms of nitrogen in fertilizers with ammonium nitrate
, urea and nitrogen kyanamidovým.

2.6.1 Soluble and insoluble nitrogen (sum)

Determination is carried out only if the above nitrogen forms
present also cyanamide.

2.6.1.1 In the absence of nitrates the sample is mineralized directly
Kjeldahl digestion.

2.6.1.2 In the presence of nitrates the sample is mineralized by Kjeldahl
decomposition after reduction with iron powder and stannous chloride.

Note:


For fertilizers with water at room temperature, leached, ammonium nitrate and
urea nitrogen (including biuret) calcium cyanamide is hydrolyzed (for
Ca (HCN2) 2) and the remaining undissolved urea-aldehyde condensates.
If it is found in the analysis of insoluble nitrogen content exceeds 0.5%,
can assume the presence of urea-aldehyde condensates respectively.
other forms of insoluble nitrogen. In this case the described analytical method without modifications
inappropriate.

2.6.2 Soluble forms of nitrogen

In various portions of single solution of the sample:

2.6.2.1 Soluble total nitrogen

2.6.2.1.1 In absence of nitrates by direct Kjeldahl digestion

2.6.2.1.2 In the presence of nitrates in aliquot part of the solution in advance
reduced by Ulsch (iron powder in an acidic environment)
Kjeldahl digestion. In both cases the ammonia down
distillation method 2.1.1.

2.6.2.2 Soluble total nitrogen without nitrate nitrogen by Kjeldahl
decomposition after elimination of nitrates with iron sulphate in acid
environment. The ammonia produced is determined by distillation method 2.1.1.

2.6.2.3 nitrate nitrogen by difference:

2.6.2.3.1 in the absence of calcium cyanamide the difference between 2.6.2.1.2 and
2.6.2.2, or between 2.6.2.1.2 (soluble total nitrogen) and
sum of ammonia and urea nitrogen (6.2 2.4 + 2.6.2.5)

2.6.2.3.2 in the presence of calcium cyanamide the difference between 2.6.2.1.2 and
2.6.2.2, or between 2.6.2.1.2 and the sum of (2.6.2.4 + 2.6.2.5 + 2.6.2.6).

2.6.2.4 Ammonia nitrogen

2.6.2.4.1 In the presence of single ammonia or ammonium and nitrate nitrogen
using distillation method 2.1.1.

2.6.2.4.2 In the presence of urea or cyanamide nitrogen
displacement of ammonia from the cold weakly alkaline medium by aeration
air. Ammonia is bound in a known volume of standard acid
sulfuric acid and determined as in distillation method 2.1.1.

2.6.2.5 Urea nitrogen

Either

2.6.2.5.1 by conversion of urea to ammonia using urease, which is titrated
hydrochloric acid solution,

And

2.6.2.5.2 by gravimetric xanthydrol; biuret will also be precipitated, but may
without major errors identified with urea nitrogen
because of its absolute content in multicomponent fertilizers is usually low,

And

2.6.2.5.3 by calculation from differences according to the table:

----------------------------------------------- -----------------------------------
- + 2-
case N - NO3 N - NH4 N - CN2 N - CO (NH2) 2

----------------------------------------------- -----------------------------------
1 absent present present (2.6.2.1.1) - (2.6.2.4.2+ 2.6.2.6)
------------------------ -------------------------------------------------- --------
2 absent present present (2.6.2.2) - (2.6.2.6 + 2.6.2.4.2)
-------------------------- -------------------------------------------------- ------
Three absent present absent (2.6.2.1.1) - (2.6.2.4.2)
---------------------------- -------------------------------------------------- ----
4 present present absent (2.6.2.2) - (2.6.2.4.2)
------------------------------ -------------------------------------------------- -

2.6.2.6 cyanamide nitrogen, by precipitation as a silver salt and determination
nitrogen in the precipitate by the Kjeldahl method.

2.6.3 Determination of different forms of nitrogen in fertilizers with ammonium nitrate and
urea nitrogen

In various portions of single solution of the sample:

2.6.3.1 Total nitrogen:

2.6.3.1.1. In absence of nitrates by direct Kjeldahl digestion,

2.6.3.1.2. the presence of nitrates in aliquot part of the solution in advance
reduced by Ulsch (iron powder in an acidic environment)
Kjeldahl digestion.
In both cases, the ammonia produced is determined by distillation method 2.1.1.

2.6.3.2 Total nitrogen without nitrate nitrogen by Kjeldahl decomposition
after elimination of nitrates iron sulphate in acid medium.
The resulting ammonia is determined by distillation method 2.1.1.

2.6.3.3 nitrate nitrogen from the difference between 2.6.3.1.2 and 2.6.3.2, or between 2.6.3.1.2
and the sum of soluble ammonia and urea nitrogen (2.6.3.4 +
2.6.3.5).

2.6.3.4 Ammonia nitrogen by displacement of ammonia from slightly alkaline cold
medium by aeration. Ammonia is bound in a known volume
standard sulfuric acid and determined as in distillation method

2.1.1.

2.6.3.5 Urea nitrogen

Either

2.6.3.5.1 by conversion of urea to ammonia using urease, which is titrated
hydrochloric acid solution,

And

2.6.3.5.2 by gravimetric xanthydrol; biuret will also be precipitated, but may
without major errors identified with urea nitrogen
because of its absolute content in multicomponent fertilizers is usually low,

And

2.6.3.5.3 by calculation from differences according to the table:
--------------------------------- --------------------------------- - +
case N - N NO3 - N, NH4 - CO (NH2 )
2 --------------------------------------------- --------------------- 1
absent present (2.6.3.1.1) - (2.6.3.4)
------- -------------------------------------------------- --------- 2
absent present (2.6.3.2) - (2.6.3.4)
--------------------- ---------------------------------------------

07.02 Determination of urea (amidic) nitrogen by photometric method

Urea reacts in an acidic environment with 4-benzaldehyde in
give yellow colored condensation product the absorbance
measured at 420 nm. The method is intended for selective determination
urea (amidic) nitrogen in single or multicomponent
fertilizers. Can not be used for fertilizers containing or releasing
substances that color compounds with
4-benzaldehyde as e.g. cyanamide, thiourea,
primary and secondary aromatic amines, and hydrazine derivatives with one
free amino group, semicarbazides.

08.02 Determination of total nitrogen Jodlbauera

Nitrates in sulfuric acid nitrate phenol to p-nitrophenol,
which is then reduced with zinc to p-aminophenol. This together with
organic component of the sample decomposed with boiling sulfuric acid for
presence of a catalyst and organically bound nitrogen
zmineralizuje. The resulting ammonium nitrogen along with the originally present
ammonium nitrogen alkalized and thereafter distilled as ammonia into a known
volume of standard sulfuric acid. Its excess is determined by titration
standard sodium hydroxide solution.

Third
Phosphorus


03.01 Methods of decomposition and extraction of phosphates

3.1.1 Decomposition with mineral acids

Sample is decomposed by boiling with a mixture of sulfuric and nitric acid, and all
phosphoric acid is thus transferred into the solution. The method is intended for
decomposition of samples of natural phosphates and fertilizers containing phosphorus if
contain larger quantities of organic substances.

3.1.2 Extraction of phosphates soluble in formic acid (2%)

Phosphates are extracted from the sample with a solution of formic acid (2%).
When it was taken up primarily of phosphates disintegrating earthy raw
phosphates, while "hard" raw phosphates are not.

3.1.3 Extraction of phosphates soluble in citric acid (2%)

Phosphates are extracted from the sample with a solution of citric acid (2%).
Method is intended primarily for fertilizers such as Thomas meal or
mixtures that contain it.

3.1.4 Extraction of phosphates soluble in neutral ammonium citrate solution


Phosphates are extracted from the sample under prescribed conditions at 65 st.
C neutral (pH = 7.0) solution of ammonium citrate.

3.1.5 Extraction of phosphates soluble in alkaline solution of ammonium citrate


3.1.5.1 Petermann at 65 st. C

Phosphates are extracted from the sample at 65 Wed.
C alkaline solution of ammonium citrate by Petermann under specified conditions.
Method is digested mainly dihydrate hydrogen - calcium phosphate
(CaHPO4.2H2O).

3.1.5.2 Petermann at room temperature

Phosphates are extracted from the sample at ca 20 Wed.
C alkaline solution of ammonium citrate by Petermann under specified conditions.
Method is intended primarily for termofosfáty respectively. thermally treated
phosphates.

3.1.5.3 Leaching by Joulieho

Phosphates are extracted from the sample at ca 20 Wed.
C alkaline solution of ammonium citrate of prescribed composition (or.
Containing 8-hydroxyquinoline to bound excess magnesium) under specified conditions
. The method is intended for the extraction of phosphorus bound in the form
aluminum calcium phosphate.

3.1.6 Extraction of phosphates soluble in water

Phosphates are extracted from the sample with water at ca 20 Wed. C for exactly

Specified conditions. The method is intended for a single-component and multicomponent
fertilizers containing water-soluble phosphates.

03.02 Methods for determination of phosphates in extracts

3.2.1 Gravimetric determination as quinolinium molybdophosphate

Method is applicable to all decomposition solutions and extracts obtained
according to par. 3.1. Containing phosphorus in the form of simple phosphates.
Polyphosphates potentially present must be hydrolyzed. From
solution acidified with nitric acid with a reagent containing
sodium or ammonium molybdate, citric acid, quinoline acid, nitric
and acetone under prescribed conditions precipitated yellow
quinolinium molybdophosphate. The precipitate is filtered
glass filtering crucible, washed, dried at 250 st. C and weighed.
In compliance with all terms containing 3.207% P2O5. Determination disturb
substances commonly present in the solution, such as mineral and organic acids, soluble silicates, etc.
.

3.2.2 Photometric determination as molybdenum blue

Method is intended particularly for determination of low phosphorus contents in organic fertilizers or
. and in other products. Sample residue after
combustion (ash) is hot-leached with hydrochloric acid and is separated by filtration
insoluble residue and silicic acid. Filtrate
Phosphate is determined photometrically after transferring to
molybdophosphate and reduction of molybdenum bound therein to molybdenum blue
metol in sulphite medium whose absorbance is measured.

3.2.3 Determination of free phosphoric acid

Aliquot of the water extract fertilizer is titrated with volumetric solution of sodium hydroxide
indicator of the dimethyl yellow to yellow color.
Identified acidity is regarded as phosphoric acid titrated to
First Instance and is expressed as free phosphoric acid.
To increase the accuracy of the color solution titrated is compared with the color shade
sodium dihydrogenphosphate solution with the same amount of indicator.
Method is intended for determining the free phosphoric acid in
superphosphates.

Fourth
Potassium


04.01 Methods of extraction of potassium

4.1.1 Extraction of acid-soluble potassium

Potassium from the sample by boiling with diluted hydrochloric acid
15 minutes. The clear solution is determined potassium.
Method is intended for mineral solid fertilizers with potassium releasable
mineral acids, as well as for various excipients
predominantly inorganic character.

4.1.2 Extraction of water soluble potassium

Soluble potassium is transferred into solution by boiling the sample with distilled water
30 minutes. The clear solution is determined potassium.
Method is intended for mineral solid, in solution and suspension fertilizers.

04.02 Methods for determination of potassium in extracts

4.2.1 Gravimetric determination as potassium tetraphenylborate

Of aliquot of the test solution before removing or disturbing effect
. interference of Bromová water, organic substances
active charcoal, excess ammonium salts by displacement of ammonia by boiling
alkalization solution, binding of interfering cations
dihydrate of disodium salt of ethylenediaminetetraacetic acid and residue ammonium
formaldehyde. Then potassium heat from slightly alkaline
precipitated sodium tetraphenylborate solution, and the precipitate was filtered off after cooling
glass filtering crucible, washed, dried at 120 st.
C and weighed. The method is suitable for all extracts of fertilizers not containing
excessive amounts of organic matter, irremovable charcoal.

4.2.2 Determination by atomic absorption spectrometry

Method is intended particularly for the determination of total potassium
organo-mineral and organic fertilizers (including manure).
The sample is burnt at 450 st. C, and the ash is decomposed with dilute hydrochloric acid
. After separation of insoluble residue and silicic acid in the solution
potassium is determined by atomic absorption spectrometry.
Admits to also determine the method of atomic emission spectrometry
(flame photometry or ICP).

Fifth
Calcium and magnesium


05.01 Methods of decomposition and leaching of calcium and magnesium

5.1.1 Decomposition with hydrochloric acid

Sample is decomposed by evaporation with diluted (1 + 1) hydrochloric acid
to dryness and potential oxidation of organic substances with several drops of acetic

Nitric acid and the insoluble residue with silicic acid are filtered
. In the filtrate after separation of sesquioxides calcium and magnesium
complexometric titration using both fluorexon (calcein) as well
on eriochrome black T. method is intended for grinding
materials made of natural materials (limestone, dolomite), or
thermal treatment (lime all types) respectively. and other materials with predominant carbonate or oxide
respectively. caustic binding of calcium and magnesium and further
silicate bond type metallurgical slags.

5.1.2 Extraction of total calcium and magnesium hydrochloric acid

Weighed sample is boiled for 30 minutes with diluted (1 + 1) hydrochloric acid
. After dilution, cooling down and making the mark the solution
filtered. The clear filtrate was used to determine. The method is intended for
samples containing calcium mostly in the form of sulphates in varying degrees of hydration
. Weighed depends calcium and sulphate content in the sample.

5.1.3 Extraction of calcium and magnesium in the water soluble

Sample charge for 30 minutes, boiled with distilled water. After dilution,
cooling down and making up to the mark, filter. The clear filtrate was used to determine
. The method is intended for fertilizers with which the fertilizer
table type prescribed content of calcium or magnesium in
water-soluble form. Weighed depends on the calcium and sulphate content.

05.02 Methods for determination of calcium and magnesium in extracts

5.2.1 Complexometric determination of calcium and magnesium

The aliquots of solutions obtained by methods 5.1.1., 5.1.2. or 5.1.3.
Were titrated with a standard solution of disodium salt of ethylenediaminetetraacetic acid
both on indicator fluorexon (calcein)
in strongly alkaline medium pH> 12 (calcium alone), and at pH 10.5
+/- 0 1 on indicator eriochrome black T (sum of calcium and magnesium).
Subtracting both consumption is found consumption of standard solution of EDTA
magnesium. Interfering metal ions are masked with potassium cyanide.

5.2.2 Determination of calcium and magnesium by atomic absorption spectrometry


Calcium or magnesium in the leachate, at a content up to 10% of CaO or MgO in
sample after appropriate dilution, the ranges of the calibration curve used for
instrument and measurement conditions determined by AAS or ICP-AES also.

5.2.3 Manganimetric determination of calcium oxalate after exclusion

For an aliquot of the extract, calcium precipitated as calcium oxalate.
He after filtering off the glass filter crucible and wash
dissolved in dilute sulfuric acid and the liberated acid is titrated with oxalic
volumetric solution potassium permanganate. The method is suitable for contents
CaO in the sample is higher than 10%.

6th
Sodium


06.01 Methods of extraction of sodium

6.1.1 Extraction of total sodium with hydrochloric acid

Sodium from sample by boiling with dilute hydrochloric acid
same manner as in method 5.1.2. The clear filtrate was used to determine
.

6.1.2 Extraction of water soluble sodium

Sodium from sample by boiling with distilled water
same manner as in method 5.1.3. The clear filtrate was used to determine.

06.02 Determination of sodium by flame photometry
Sodium
after optional dilution aliquot of the leachate 6.1.1.
or 6.1.2. within the calibration range of the instrument used and the conditions
measurement it is determined by atomic emission spectrometry, respectively. ICP-AES.
Admits determination by atomic absorption spectrometry.

7th
Sulfur


07.01 Methods of extraction of sulfur in various forms

7.1.1 Extraction of total sulphate sulfur

Sulphate is extracted from the sample 30 minutes boiling with diluted (1 + 1) hydrochloric acid
. In aliquot part of clear filtrate down sulphates.
Sample charge depends on the content of sulphates and calcium.

7.1.2 Extraction of various forms of total sulfur

The method is intended for fertilizers containing sulfur in elementary form,
thiosulphates, sulphites or. sulphates. Boiling of the sample with a solution of sodium hydroxide
in strongly alkaline environments
elemental sulfur is converted to polysulphide and thiosulphate with potentially
sulfite present in the following step, oxidized with hydrogen peroxide to
sulfate. Throughout clear filtrate or an aliquot of the down
sulphates.

7.1.3 Extraction of water soluble sulphate sulfur


Water-soluble sulphates from the sample 30 minutes boiling with
distilled water. After dilution, cooling down and making up to the mark
solution is filtered and an aliquot of the filtrate is determined sulphates.

7.1.4 Extraction of various forms of water-soluble sulfur

The method is intended for fertilizers containing water-soluble sulfur in the form
thiosulfate, sulfite, respectively. sulphate. The sample is shaken in the cold for 30 minutes
with distilled water. In aliquot part of clear filtrate after alkalization
boiling with hydrogen peroxide oxidized thiosulphate and sulphite to sulphate
which, after acidification, together with the magnesium originally present down.

07.02 Gravimetric determination of sulfur in extracts

In the extracts obtained by methods 7.1.1, 7.1.2, 7.1.3 or 7.1.4 with either
whole volume or aliquot chloride in acid medium
barium precipitated barium sulfate was filtered off, ignite and weigh.

07.03 Determination of elemental sulfur

Elemental sulfur is extracted from the sample in a Soxhlet apparatus
carbon disulphide. Sulfur extracted is determined by weighing. If necessary,
checked purity obtained and weighted sulfur sublimation and weighing the residue.

8th


Chloro-
08.01 Determination of chlorides in the absence of organic substances

Chlorides leached from sample water is determined according to Volhard.
Collide with excess of standard solution of silver nitrate in an acidic environment
. The excess is titrated with a standard solution of ammonium thiocyanate
in the presence of ammonium ferric sulphate.

9th
Trace elements


09.01 Determination of trace elements at a content exceeding 10%

9.1.1 Extraction

9.1.1.1 Extraction of total content of trace elements

Trace elements are leached from the sample with boiling diluted hydrochloric acid
under specified conditions.

9.1.1.2 Extraction of water-soluble forms of trace elements

Trace elements are leached from the sample water 20 Wed. C
under exactly defined conditions.

9.1.2 Determination of trace elements in extracts:

9.1.2.1 Determination of manganese, copper, cobalt, zinc and iron by atomic absorption spectrometry


Leachates after any possible restrictions interferences diluted so that
concentrations of the element in the optimum measuring range of
spectrometer at the appropriate wavelength for compliance with all procedures
instructions provided by the manufacturer of the device.

9.1.2.2 Determination of boron by spectrophotometric

3- ions BO3 - forms with azomethine H pH (5.2 +/- 0.2)
yellow complex. Absorbance of the solution is measured at 410 nm.

9.1.2.3 Spectrophotometric determination of molybdenum

In acidic medium consists of Mo (V) ions, SCN - yellow-orange complex
(MoO (SCN) 5). The complex is extracted into n-butyl acetate.
Interfering ions remain in the aqueous phase. The absorbance of the yellow-orange complex is measured
at a wavelength of 470 nm.

09.02 Determination of trace elements in the content exceeding 10%

9.2.1 Extraction

9.2.1.1 Extraction of total content of trace elements

Trace elements are leached from the sample with boiling diluted hydrochloric acid
under specified conditions.

9.2.1.2 Extraction of water-soluble forms of trace elements

Trace elements are leached from the sample water 20 Wed. C
under exactly defined conditions.

9.2.2 Determination of trace elements in extracts:

9.2.2.1 Determination of zinc and iron by atomic absorption spectrometry


Leachates after any possible restrictions interferences diluted so that
concentrations of the element in the optimum measuring range of
spectrometer at the appropriate wavelength for compliance with all procedures
instructions provided by the manufacturer of the device.

9.2.2.2 Determination of boron acidimetric titration

Very weak boric acid with D-mannitol (as well as other
org. Materials with higher content of OH groups) stronger manitoboritou
acid which may be titrated with standard sodium hydroxide solution until pH = 6
'3.

9.2.2.3 Determination of cobalt by gravimetric method

Cobalt (III) gives the 1-nitroso-2-naphthol red precipitate
Co (C10H6ONO) 3.2H2O. Cobalt is precipitated in acetic acid
solution of 1-nitroso-2-naphthol. The precipitate was filtered and washed and dried
to constant weight and weighed as Co (C10H6ONO) 3.2H2O.

9.2.2.4 Determination of copper by titration method

Cuprous ions in the weakly acidic medium reduces potassium iodide

To cuprous. Iodine is titrated with standard sodium thiosulfate solution
in the presence of starch as an indicator.

9.2.2.5 Determination of manganese by titration method

Chloride ions present in the extract are eliminated by boiling sulfuric acid
. Manganese is oxidized bismuthate in a nitric acid medium.
The permanganate is reduced with a ferrous sulfate solution. His
excess is titrated with a standard solution of potassium permanganate.

9.2.2.6 Determination of molybdenum by gravimetric method

8-hydroxyquinoline (oxine) with molybdenum in slightly acidic medium in the presence
EDTA precipitate. The yellow precipitate was
filtered, washed and dried to constant weight as MoO2 (C9H6ON) second

10th

Risk elements

1.10 Determination of hazardous elements in inorganic fertilizers and raw materials for their production


10.1.1 Extraction of total content of hazardous elements

Hazardous elements are leached with boiling mixture of nitric acid and hydrochloric
under specified conditions.

10.1.2 Determination of hazardous elements in extracts:

10.1.2.1 Determination of chromium, cadmium and lead by atomic absorption spectrometry


Leachates after the eventual elimination of interferences diluted so that the concentration
fixed element in the optimum measuring range of
spectrometer at the appropriate wavelength for compliance with all procedures
instructions provided by the manufacturer of the device.

10.1.2.2 Determination of arsenic absorption spectrometry method

Extracts Sample arsenic is reduced with potassium iodide to As (III).
The iodide was removed by addition of ascorbic acid. In the apparatus for continuous generation
hydrides arsine is formed by reaction with sodium borohydride
a stream of inert gas to the decomposition
tube, where pyrolytic atomization.

10.1.2.3 Determination of mercury absorption spectrometry method

The determination is used a single-type analyzer (TMA, AMA)
in which the sample is decomposed by pyrolysis in an oxygen stream. Mercury is captured on
amalgamator. Mercury from the amalgamator by heating and measured its absorbance
.

2.10 Determination of hazardous elements in organic fertilizers and raw materials for their production


10.2.1 Extraction of total content of hazardous elements

Hazardous elements are leached with boiling mixture of nitric acid and hydrochloric
(Lefort aqua regia) under specified conditions.

10.2.2 Determination of hazardous elements in extracts:

10.2.2.1 Determination of chromium, cadmium, copper, molybdenum (ETA), nickel, lead and zinc
method of absorption spectrometry

Leachates after any possible restrictions interferences diluted so that the concentration
fixed element in the optimum measuring range of
spectrometer at the appropriate wavelength for compliance with all procedures
instructions provided by the manufacturer of the device.

10.2.2.2 Determination of arsenic absorption spectrometry method

Arsenic is determined as described in paragraph 10.1.2.2.

10.2.2.3 Determination of mercury absorption spectrometry method

Mercury is determined as described in paragraph 10.1.2.3.

11th

Determination of free sulfuric acid

Aliquot of the water extract fertilizer is titrated with volumetric solution of sodium hydroxide
mixed indicator. Observed acidity is considered
sulfuric acid.

12th

Determination of combustible substances

Organic portion in the sample (combustible substances) is determined from the weight loss
(after pre-drying the sample at 105 st. C) after combustion of the sample at 450
st. C to constant weight.

13th
Determination of moisture


The moisture content is determined gravimetrically by weight loss after drying
sample at the prescribed temperature and time.

14th

The pH value

The pH was determined by measuring the extract or the suspension of the sample to pH
meter with usual combination of electrodes using two buffers
under given measuring conditions prescribed manner.

15th
Determination of conductivity


Conductivity of aqueous extract of the sample is measured with a conductivity meter
appropriate electrode under given measuring conditions (temperature)
manner prescribed for the type of fertilizer.

16th
Determination of particle size


The sample is placed on the testing screen with given nominal size of the holes
and shaking, tapping (dry) or washing (wet) shares
on Undersize and oversize share at the prescribed conditions. weighing

Individual fractions is determined by their percentage representation. ".

Third after Annex no. 2 supplementing the Annex no. 3, which reads:

" Příl.3
Methods of microbiological tests


First Thermotolerant coliform bacteria, enterococci and Salmonella
determined by cultivation methods of direct seeding on selective agar media
. In the method of direct sowing, it is assumed that each
colony grown on this culture medium, the propagation
population derived from a single cell or one kolonitvorné unit
which were present in the extract sample or a dilution in
time of vaccination.

Second The procedure is considered adequate if it complies with the requirements arising from
ISO cited under point. ) and if
adhered to the methods specified under point. b) to d):

A)

ISO - 6887: Microbiology. General guidelines for the preparation of dilutions in
microbiological testing.

ISO - 7218: Microbiology of food and animal feed.
General guidelines for microbiological testing.

ISO - 8199: Water quality. General guidelines for the determination of microorganisms
cultivation methods.

ISO - 9998: Water quality. Monitoring and evaluation culture media for
determine the number of colonies used in water quality testing.

B) Method for determination of thermotolerant coliform bacteria:

ISO - 9308-1: Microbiology. General guidelines for determining the number
coliform bacteria. Colony count technique.

C) method for the determination of enterococci:

ISO - 7899-2: Water quality. Determination of faecal streptococci
Part 2: Membrane filtration method - modified.

D) Method for detection of Salmonella:

EN 12824: Microbiology of food and animal feed.
Horizontal method for the detection of Salmonella. ". Article II





Effectiveness This Decree shall take effect on 1 January 2001.

Minister:

Ing. Fencl vr