Decree of the Ministry of Agriculture No. 273 / 1998 Coll.
Decree of the Ministry of Agriculture on collection and chemical analysis of fertiliser samples
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Effective from 30.11.1998
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30.11.1998
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273
DECLARATION
Ministry of Agriculture
of 12 November 1998
on fertiliser sampling and chemical analysis
According to Section 16 (b) of Act No. 156 / 1998 Coll., on fertilizers, soil aids, auxiliary plant preparations and substrates and on agrochemical testing of agricultural soils (Fertilisers Act), the Ministry of Agriculture provides:
Sampling of fertilisers, soil aids, plant aids, substrates and manure
For the purposes of this decree:
(a) lots of such quantities of fertilisers, soil improvers, auxiliary plant products, substrates or manure (hereinafter referred to as "products") which constitute a single whole by their characteristics, labelling and spatial arrangement;
(b) a partial sample of the quantity of the product obtained by a single sample of the lot;
(c) by aggregate sample, a set of individual incremental samples taken from the lot;
(d) by a reduced aggregate sample, a subquantity of the aggregate sample with the same composition as the aggregate sample,
(e) by the final sample, the incremental quantity of the aggregate or reduced aggregate sample required for the test.
The sampling of products shall include the taking of incremental samples, the creation of aggregate and final samples, the storage and labelling of final samples, including the drawing up of a sampling report.
(1) For sampling they are used for:
(a) the rigid products, the mechanical devices of the manufacturer, directly intended to be used for the sampling of products in motion or moving during sampling, as well as samples, such as tubular, flat blades and spiral samples, suitable for the size of the lot and the product particles;
(b) liquid products of the sampling pump, the lower-end sampling tube and the sampling vessel.
(2) A divider is used to divide the sample and, exceptionally, the sample is divided by quarts.
(3) The sampling aids cannot be of material which would affect the quality of the product sample.
(1) If the lot is so large or stored that it is not possible to take individual incremental samples from it, only the part thereof shall be considered a lot which allows the incremental samples to be taken.
(2) In the case of products intended solely for consumer use (1), the contents of a single original package, which at the same time constitutes an aggregate sample, are considered a lot. Where the weight of the contents of the package is insufficient, the number of packages shall be taken to meet the requirement of weight of the final sample.
(1) The weight of the incremental sample taken from bulk products, packaged products with a weight of more than 50 kg or a volume of more than 50 l shall be at least 200 g, except for the incremental sample taken from the moving product by mechanical equipment.
(2) The minimum number of incremental samples per lot size and product type is given in Annex 1.
(3) One aggregate sample shall be produced from incremental samples taken from one lot. In the same way, 2 aggregate samples shall be produced if, for products which consist of more than 1 type-determining component and which have a tendency to break the mixture, a tube sampling device is used for sampling.
(4) The aggregate sample shall be reduced to a final maximum weight of 4 kg. The aggregate sample of one-component ammonium nitrate products with a nitrate nitrogen content of more than 28% for which the explosive tests are carried out at the same time shall not exceed 75 kg.
(1) A minimum of 3 final samples shall be produced from each aggregate sample or from each reduced aggregate sample.
(2) The weight of the final sample of solid products is at least 1 kg, liquid products at least 500 g.
(3) In the case of packs and containers containing up to 1 kg, the contents of the packages or their set are the final sample.
(4) The weight of the final sample of single-component ammonium nitrate products with a nitrate nitrogen content of more than 28% for which the explosive tests are carried out at the same time is not more than 25 kg.
(1) The sampling aids, work areas and sampling vessels must be clean and dry.
(2) Partial samples shall be taken at random from the whole lot. The mass or volume of incremental samples taken is approximately the same.
(3) A lot of solid products, unpacked or in packages of over 100 kg, are to be allocated in notional terms to approximately the same parts and at least 1 incremental sample taken from each.
(4) A partial sample shall be taken from the selected packaging of a solid product of 100 kg or less by means of a tube sampling device or by repeatedly dividing the entire contents of the package into dividers.
(5) A partial sample shall be taken from the liquid product after mixing, emulsions, suspensions and cashew mixtures only from the stream of the flowing product.
(6) If it contains an aggregate sample of clumps, they shall be crushed separately and reassembled with the aggregate sample. The original aggregate sample shall be used to determine the particle size.
(7) The final samples shall be kept for a period of 6 months from the date of completion of the sampling report in clean, dry, moisture-free, airtight and closed packages made of materials which do not affect their quality. After the closure of the container, the seal, sealing tape or a combination of these devices shall be sealed so that the container cannot be opened without damaging the safety. The label of the final sample with at least the following particulars shall also be attached to the packaging:
(a) the name and type of product,
(b) by name and receipt (hereinafter referred to as the name), residence and, where appropriate, the identification number of the natural person or the commercial name, registered office and, where appropriate, the identification number of the legal person who supplied, imported or produced the product;
(c) the name and address of the Central Audit and Examination Institute of the Agricultural Institute (hereinafter referred to as the Institute) or, where appropriate, the name of the staff member who took the sample;
(d) the date of sampling and the place where it was taken;
(e) the number of the sampling report.
(8) Final samples are kept by the Institute. The Institute shall draw up a sampling report for each final sample containing the following information:
(a) the name, address and, where appropriate, the identification number of the natural person or the trade name, registered office and, where appropriate, the identification number of the legal person who supplied, imported or manufactured the product from which the sample was taken;
(b) the name and type of product sampled;
(c) the size and type of the lot, the content of each part of the product, the form of nutrients and their solubility;
(d) the name and address of the Institute and, where appropriate, the name of the staff member of the Institute that took the sample;
(e) the place and date of sampling;
(f) type of packaging and storage;
(g) the order number or the order bill number or, where applicable, the means of transport from which the sample was taken;
(h) the relevant facts established when sampling, the names and signatures of the responsible persons;
(i) the protocol number.
Chemical analyses, biological tests and tests
Chemical analyses of products shall be carried out using the procedures set out in Annex 2.
(1) Biological tests and tests shall be carried out by the Institute in the field, greenhouse, vegetation hall or laboratory.
(2) Biological tests and tests shall be carried out by:
(a) the product is verified on the crops for which it is intended;
(b) the nature and the declared use of the product derive from the selection of the type of test and the site, the length of the verification, the variants of the test and the parameters evaluated;
(c) at least one comparative control option shall be included in the biological tests;
(d) in biological tests, the certified variants have at least 4 repetitions.
(3) Microbiological tests shall be carried out using the methods set out in Annex 3.
This decree shall take effect on the day of its publication.
Minister: Ing. Fencl v. r.
Příloha č. 1
Annex No. 1 to Decree No. 273 / 1998 Coll.
Minimum number of incremental samples by product type and batch size
| druh výrobku a velikost partie | minimální počet dílčích vzorků |
|---|---|
| TUHÉ VÝROBKY | |
| volně ložené tuhé výrobky nad 100 kg | |
| počet vzorků | |
| 7 | |
| druhá odmocnina z dvacetinásobku hmotnosti | |
| 40 | |
| balené tuhé výrobky v obalech do obsahu 100 kg | |
| balení s obsahem větším než 1 kg | počet balení |
| do 4 kusů | všechna |
| 5 až 16 kusů | 4 |
| 17 až 400 kusů | druhá odmocnina z počtu balení, zaokrouhleno na celá čísla |
| nad 400 kusů | 20 |
| balení s obsahem do 1 kg | |
| 4 | |
| KAPALNÉ VÝROBKY | |
| volně ložené kapalné výrobky v cisternách nad 100 kg | |
| počet vzorků | |
| 7 | |
| druhá odmocnina z dvacetinásobku hmotnosti | |
| 40 | |
| balené kapalné výrobky v nádobách do obsahu 100 kg | |
| balení s obsahem větším než 1 kg | počet nádob |
| do 4 kusů | všechny |
| 5 až 16 kusů | 4 |
| 17 až 400 kusů | druhá odmocnina z počtu nádob, zaokrouhleno na celá čísla |
| nad 400 kusu | 20 |
| nádoby s obsahem do 1 kg | |
| 4 | |
Příloha č. 2
Annex No 2 to Decree No. 273 / 1998 Coll.
Chemical analysis procedures
1. Preparation of samples for analysis
The modification of the final sample delivered to the laboratory is a sequence of operations, most often sifting, diluting and homogenisation, which is carried out in such a way that:
(a) even the smallest of the samples envisaged by the analytical methods are representative of the final sample;
(b) during the treatment, the granularity of the fertiliser has not been changed enough to significantly affect solubility in various leaching agents
2. Nitrogen
2.1. Determination of ammonium nitrogen
2.1.1 Determination of ammonium nitrogen by distillation method
Ammonia is extracted with excess sodium hydroxide, distilled and bound in a known volume of a volumetric solution of sulphuric acid, the excess of which is determined by titration with a volumetric solution of sodium hydroxide.
2.1.2 Determination of ammonium nitrogen by formaldehyde method
Ammonium ions in an aqueous solution are converted to virtually neutral hexamethylenetetramine by reaction with formaldehyde, thereby releasing equivalent amounts of oxonium ions. These are determined directly by titration by a volumetric solution of sodium hydroxide to phenolphthalein.
2.2. Determination of ammonium and nitrate nitrogen according to Devard
Nitrates and possibly present nitrites in a highly alkaline environment are reduced by hydrogen in the state of birth, resulting in a reaction of Devard's sodium hydroxide alloy. The ammonia produced is distilled together with the initially present and bound in a known volume of a volumetric solution of sulphuric acid, the excess of which is determined by titration with a volumetric solution of sodium hydroxide.
2.3. Determination of total nitrogen (sum of inorganic and organically bound nitrogen)
2.3.1 Determination of total nitrogen in nitrate-free nitrogen lime
The sample shall be broken down by the Kjeldahl method by boiling with sulphuric acid in the presence of a copper catalyst. The resulting ammonium sulphate is extracted with sodium hydroxide and distilled into a known volume of a volumetric sulphuric acid solution, the excess of which is determined by titration with a volumetric sodium hydroxide solution.
2.3.2 Determination of total nitrogen in nitrogen lime with nitrate
First, metal iron (powder) and tin chloride are reduced to ammonia and the sample is further decomposed by Kjeldahl as in paragraph 2.3.1.
2.3.3 Determination of total nitrogen in urea
The urea nitrogen is converted by boiling the sample with sulphuric acid into ammonium, which is distilled from the alkaline environment into a known volume of the volumetric sulphuric acid solution and the excess is determined by titration with a volumetric solution of sodium hydroxide.
2.4. Determination of cyanide nitrogen
Cyanamide is precipitated from the solution as a silver salt which is decomposed by the Kjeldahl method and the nitrogen is determined as in paragraph 2.3.1.
2.5. Determination of biurete in urea
Biuret forms a blue-violet water-soluble complex in an alkaline environment in the presence of sodium potassium tartrate with bivalent copper, whose absorbance is measured at a wavelength of 546 nm.
2.6. Determination of different forms of nitrogen side by side
Determination of different forms of nitrogen side by side in fertilisers with ammonium, nitrate, urea and cyanamide nitrogen
2.6.1 Solvent and insoluble nitrogen (sum)
Determination shall be made only if cyanide is also present from the above forms of nitrogen.
2.6.1.1. In the absence of nitrates, the sample is directly mineralized by Kjeldahl decomposition.
2.6.1.2. In the presence of nitrates, the sample is mineralized by Kjeldahl's decomposition after reduction of powdered iron and tin chloride.
Note:
The fertiliser is separated by water at room temperature from ammonium, nitrate and urea nitrogen (including biureth), calcium cyanide is hydrolysed (Ca (HCN2) 2) and urea-aldehyde condensates remain undissolved. If the insoluble nitrogen content is found to be more than 0,5%, the presence of urea-aldehyde condensates or other forms of insoluble nitrogen may be considered. In this case, the analytical procedure described is inappropriate without modification.
2.6.2 Solvent forms of nitrogen
The different proportions of a single sample solution shall be determined by:
2.6.2.1 soluble total nitrogen
2.6.2.1.1. In the absence of nitrates by direct degradation according to Kjeldahl
2.6.2.1.2. In the presence of nitrates in the aliquot proportion of the solution previously reduced according to Ulsche (powder iron in acidic environment) by decomposition according to Kjeldahl. In both cases, the produced ammonia is determined by the distillation method 2.1.1.
2.6.2.2 the soluble total nitrogen without nitrate nitrogen Kjeldahl decomposition after removal of nitrate with iron sulphate in an acidic environment. The produced ammonia is determined by the distillation method 2.1.1.
2.6.2.3. Nitrate nitrogen from the difference:
2.6.2.3.1 in the absence of calcium cyanide, the difference between 2.6.2.1.2 and 2.6.2.2.2 or between 2.6.2.1.2 (soluble total nitrogen) and the sum of ammonium and urea nitrogen (2.6.2.4 + 2.6.2.5),
2.6.2.3.2 in the presence of calcium cyanide, the difference between 2.6.2.1.2 and 2.6.2.2 or between 2.6.2.1.2 and the sum (2.6.2.4 + 2.6.2.5 + 2.6.2.6).
2.6.2.4 Ammonium nitrogen
2.6.2.4.1 in the presence of ammonium or ammonium and nitrate nitrogen alone, using distillation method 2.1.1.
2.6.2.4.2 in the presence of urea or cyanamide nitrogen, by sealing ammonia in the cold from a weak alkaline environment through air. The ammonia is bound in a known volume of a volumetric solution of sulphuric acid and determined as in the distillation method 2.1.1.
2.6.2.5. Urea nitrogen
either
2.6.2.5.1 by converting urea by means of urease into ammonia, which is titrated with a graduated hydrochloric acid solution,
or
2.6.2.5.2 by weight xanthhydrol; the biuret is also precipitated, but can be identified with urea nitrogen without great error, since its absolute content in compound fertilisers is generally small,
or
2.6.2.5.3. calculation of differences according to the table:
| případ | ||||
| 1 | nepřítomen | přítomen | přítomen | (2.6.2.1.1) - (2.6.2.4.2 + 2.6.2.6) |
| 2 | přítomen | přítomen | přítomen | (2.6.2.2) - (2.6.2.4.2 + 2.6.2.6) |
| 3 | nepřítomen | přítomen | nepřítomen | (2.6.2.1.1) - (2.6.2.4.2) |
| 4 | přítomen | přítomen | nepřítomen | (2.6.2.2) - (2.6.2.4.2) |
2.6.2.6. Cyanamide nitrogen precipitated as silver salt and by determination of nitrogen in the precipitate according to Kjeldahl.
2.6.3 Determination of different forms of nitrogen side by side in fertilisers with ammonium, nitrate and urea nitrogen
The different proportions of a single sample solution shall be determined by:
2.6.3.1. Total nitrogen:
2.6.3.1.1. In the absence of nitrates by direct degradation according to Kjeldahl,
2.6.3.1.2. In the presence of nitrates in the aliquot proportion of the solution previously reduced according to Ulsche (powder iron in acidic environment) degradation according to Kjeldahl.
In both cases, the produced ammonia is determined by the distillation method 2.1.1.
2.6.3.2. Total nitrogen without nitrate nitrogen Kjeldahl decomposition after removal of nitrate with iron sulphate in acidic environment. The produced ammonia is determined by the 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 ammonium and urea nitrogen (2.6.3.4 + 2.6.3.5).
2.6.3.4. Ammonium nitrogen by sealing ammonia through the cold from a weak alkaline environment through air. The ammonia is bound in a known volume of a volumetric solution of sulphuric acid and determined as in the distillation method 2.1.1.
2.6.3.5. Urea nitrogen
either
2.6.3.5.1 by converting urea by means of urease into ammonia, which is titrated by a graduated hydrochloric acid solution,
or
2.6.3.5.2. Weighted xanthhydrol; the biuret is also precipitated, but can be identified with urea nitrogen without great error, since its absolute content in compound fertilisers is generally small,
or
2.6.3.5.3 by calculation of differences in the table:
| případ | |||
| 1 | nepřítomen | přítomen | (2.6.3.1.1) - (2.6.3.4) |
| 2 | přítomen | přítomen | (2.6.3.2) - (2.6.3.4) |
2.7. Determination of urea (amidical) nitrogen by photometric method
Urea reacts in an acidic environment with 4-dimethylaminobenzaldehyde to produce a yellow coloured condensation product whose absorbance is measured at a wavelength of 420 nm. The method is intended for selective determination of urea (amidic) nitrogen in both single and compound fertilisers. It cannot be used for fertilisers containing or releasing substances that also form colour compounds with 4-dimethylaminobenzaldehyde, such as cyanamide, thiourea, primary and secondary aromatic amines, hydrazine and derivatives with one free amino group, semicarbazides.
2.8. Determination of total nitrogen according to Jodlbauer
Nitrates in the sulphuric acid environment reduce phenol to p-nitrophenol, which is then reduced by zinc to p-aminophenol. This, together with the organic component of the sample, is decomposed by boiling sulphuric acid in the presence of a catalyst, whereby organically bound nitrogen is zineralised. The produced ammonium nitrogen, together with the originally present ammonium nitrogen after alkalisation, is distilled as an ammonia into a known volume of a volumetric sulphuric acid solution. The excess is determined by titration with a graduated sodium hydroxide solution.
3. Phosphorus
3.1. Methods of degradation and leaching of phosphates
3.1.1. Mineral acid decomposition
The sample is broken down by boiling with a mixture of sulphuric acid and nitric acid and all phosphoric acid is transferred to the solution. The method is intended for the degradation of samples of natural phosphate and phosphorus-containing fertilisers unless they contain more organic substances.
3.1.2. Phosphates soluble in formic acid (2%)
Phosphates are extracted from the sample with formic acid solution (2%). In doing so, phosphates are excluded mainly from the crumbling earth of crude phosphates, whereas "hard" crude phosphates are not excluded.
3.1.3. Extraction of citric acid-soluble phosphates (2%)
Phosphates are extracted from the sample with citric acid solution (2%). The method is mainly intended for fertilisers of the Thomas meal type or mixtures containing it.
3.1.4. Extraction of phosphates soluble in neutral ammonium citrate solution
Phosphates are extracted from the sample under prescribed conditions at 65 ° C by neutral (pH = 7,0) solution of ammonium citrate.
3.1.5. Extraction of phosphates soluble in basic ammonium citrate solution
3.1.5.1. Casting according to Petermann at 65 ° C
Phosphates are extracted from the sample at 65 ° C with an ammonium citrate base solution according to Petermann under specified conditions. The method consists primarily of hydrogen phosphate (CaHPO4.2H2O) dihydrate.
3.1.5.2. Flexing according to Petermann at room temperature
Phosphates are extracted from the sample at about 20 ° C with the basic ammonium citrate solution according to Petermann under specified conditions. The method is mainly designed for thermophosphates or thermically processed phosphates.
3.1.5.3. Joulie's excavation
Phosphates are extracted from the sample at about 20 ° C with an alkaline solution of ammonium citrate of the prescribed composition (or containing 8-hydroxyquinoline to bind magnesium excess) under specified conditions. The method is intended for the extraction of phosphorus bound in the form of alumina phosphate.
3.1.6. Exclusion of water-soluble phosphates
Phosphates are extracted from the sample with water at about 20 ° C under specified conditions. The method is intended for single and compound fertilisers containing water-soluble phosphates.
3.2. Methods for the determination of phosphates in leases
3.2.1. Weight determination as phosphomolibdenan quinoline
The method shall be applicable to all degradation solutions and leases obtained in accordance with paragraph 3.1., containing phosphorus in the form of simple phosphates. Alternatively present polyphosphates must be hydrolysed in advance. From a solution acidified with nitric acid with a solvent containing molybdenum sodium or ammonium, citric acid, quinoline, nitric acid and acetone, the yellow molybdenum phosphate of quinolinium precipitates under the prescribed conditions. The clot is filtered with a glass filter cup, washed, dried at 250 ° C and weighed. With all conditions it contains 3,207% P2O5. Determination does not disturb substances usually present in the solution, such as mineral and organic acids, soluble silicates, etc.
3.2.2. Photometric determination as molybdenum blue
The method is intended primarily for the determination of low phosphorus levels in organic fertilisers and other products. The rest of the sample after incineration (ash) is eliminated with hydrochloric acid and separated by filtration by insoluble residue and silicon acid. In the filter, the photometric determination of phosphate after conversion into molybdenum phosphate and the reduction in molybdenum-bound molybdenum to molybdenum blue by meta in a sulphite medium whose absorbance is measured.
3.2.3 Determination of free phosphoric acid
The aliquot fraction of the fertiliser water leaching is titrated with a graduated solution of sodium hydroxide to indicate dimethyl yellow in yellow. The acidity found is considered as phosphoric acid titrated to the first degree and expressed as free phosphoric acid. To increase the accuracy, the colour of the titrated solution is compared to that of the sodium dihydrogen phosphate solution with the same amount of indicator. The method is intended for the determination of free phosphoric acid in superphosphates.
4. Potassium
4.1. Methods of potassium leaching
4.1.1. Extraction of acid-soluble potassium
Potassium is extracted from the sample with a diluted hydrochloric acid for 15 minutes. Potassium is determined in a clear solution. The method is intended for both mineral solid fertilisers with potassium-released mineral acids and for various excipients of a predominantly inorganic nature.
4.1.2. Exclusion of water-soluble potassium
The water-soluble potassium is added to the solution by boiling the sample with distilled water for 30 minutes. Potassium is determined in a clear solution. The method is intended for mineral solid, solution and suspension fertilisers.
4.2. Methods for determination of potassium in leases
4.2.1. Weighted determination as potassium tetraphenylborate
From the aliquot of the test solution, the interference or presence of cyanamide by oxidation of bromine water, organic substances by active carbon, excess ammonium salts by sealing ammonia by boiling in a calcined solution, binding of disruptive cation with disodium salt of ethylenediaminetetraacetic acid and the rest of ammonium ions by formaldehyde is removed. Then potassium is precipitated from a slightly alkaline environment with sodium tetrafylborate solution and the precipitate is filtered after cooling with a glass filter cup, washed, dried at 120 ° C and weighed. The method is suitable for all fertiliser leaching if they do not contain an excessive quantity of organic substances, not removable by activated carbon.
4.2.2 Determination of atomic absorption spectrometry method
The method is intended primarily for the determination of total potassium in organo-mineral and organic fertilisers (including manure). The sample is burned at 450 ° C and the ash is distributed with dilute hydrochloric acid. After separation of insoluble residue and silica acid in the solution, potassium is determined by the atomic absorption spectrometry method. The atomic emission spectrometry method (flame photometry or ICP) is also allowed.
5. Calcium and magnesium
5.1. Methods of decomposition and leaching of calcium and magnesium
5.1.1. Hydrochloric acid decomposition
Dispose of the sample by evaporation with dilute (1 + 1) hydrochloric acid to dry and, if necessary, by oxidation of organic substances by several drops of nitric acid and the insoluble residue with excluded silica acid is filtered. In the filtration, calcium and magnesium are determined after the separation of secvioxides by complex titration on both fluoroexon (calcein) and on the eriochromic black T. The method is intended for materials produced by grinding of natural substances (limestone, dolomites) or by thermal treatment (lime of all types) or other matter with predominant carbonate or oxide or hydroxide binding of calcium and magnesium and silicate binding of the metallurgical slag type.
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Regulation Information
| Citation | Decree of the Ministry of Agriculture No. 273 / 1998 Coll., on collection and chemical analysis of fertiliser samples |
|---|---|
| Regulation Type | Order |
| Author | - |
| Collection | Code of Laws |
| Date of Promulgation | 30.11.1998 |
|---|---|
| Effective from | 30.11.1998 |
| Effective until | - |
| Status | Valid |
Legal Areas:
Administrative law
Agriculture
The regulation text is for informational purposes only.
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