EN 16032-2011 pdf download.Fertilizers – Extraction and determination of elemental sulfur.
This EN 16032 specifies a method for extraction and determination of the elemental sulfur contained in fertilizers.
The method is applicable to [C fertilizers for which a declaration of the total sulfur in elemental form is provided for in Regulation (EC) Nr 2003/2003, Annex I [1].
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (Including any amendments) applies.
EN 1482-2, Fertilizers and liming materials — Sampling and sample preparation — Part 2: Sample preparation
EN 12944-1:1999, Fertilizers and liming materials and soil improvers — Vocabulary— Part 1: General terms EN 12944-2:1999, Fertilizers and liming materials and soil improvers — Vocabulary— Part 2: Terms relating to fertilizers
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 12944-1:1999 and EN 12944-2:1999
apply.
4 Principle
After the removal of soluble compounds, elemental sulfur is extracted by using carbon disulfide, followed by gravimetric determination of the sulfur extracted,
WARNING — This method of analysis involves the use of carbon disuifide (CS2). Special safety measures shall therefore be taken, In particular with regard to:
the storage of CS2:
— protective equipment for staff:
— occupational hygiene:
— prevention of fire and explosions;
7.3 Vacuum rotary evaporator.
7.4 Electric oven, fan assisted, set at (90 ± 2) °C.
7.5 PorcelaIn Petrl dishes, 50 mm to 70 mm in diameter, not exceeding 50 mm in height.
7.6 ElectrIc hot plate, with adjustable temperature.
8 Procedure
8.1 Test portion
Weigh to an accuracy of 1 mg, 5g to lOg of the laboratory sample and place the test portion (m) in the
thimble of the Soxhiet apparatus (7.2).
8.2 Extraction of the sulfur
Wash thoroughly the contents with hot water to remove all soluble compounds. Dry in the electric oven (7.4) at 90 °C for at least 1 h. Place the filter in the Soxhlet apparatus (7.2).
Place a few glass beads in the flask of the apparatus (7.1) and weigh (rno). then add 50 ml of carbon disulfide
(6.1).
Connect the apparatus and leave the elemental sulfur to be extracted for 6 h. Switch off the heat and, after cooling, disconnect the flask. Connect the flask to the rotary evaporator (7.3) and evaporate until the contents of the flask have solidified in a spongy mass.
Dry the flask In the electric oven (7.4) at 90 C (generally 1 h is necessary) until a constant mass is obtained (rn).
8.3 Determination of the purity of the elemental sulfur
Certain substances may have been extracted by the carbon disulfide at the same time as the elemental sulfur. The purity of the elemental sulfur is determined as follows:
Homogenize the contents of the flask as thoroughly as possible, and remove 2 g or 3 g, weighed to an accuracy of 1 my (n). Weigh the Petri dish (in2) and place the aliquot in it. Place on the hot plate (7.6) set at a temperature not exceeding 220 C so as not to cause combustion of the sulfur. Continue sublimation for 3 h or 4 Ii until a constant mass is obtained (in3).
NOTE Only compounds with boiling point < the temperature of the hotplate will be removed.
in is the mass of the test portion, in grams;
m0 is the mass of the Soxhlet flask, In grams;
ni is the mass of the Soxhiet flask and the impure sulfur after drying, in grams; i, is the mass of the impure sulfur to be purified, in grams:
n2 is the mass of the Petri dish, in grams;
m3 is the mass of the Petri dish after sublimation of the sulfur, in grams.
10 Test report
The test report shall contain at least the following information:
a) all information necessary for the complete identification of the sample:
b) the test method used with reference to this European Standard (i.e. EN 16032);
c) the test results obtained:
d) date of sampling and sampling procedure (if known);
e) date when the analysis was finished;
f) whether the requirement of the repeatability limit has been fulfilled:
g) all operating details not specified in this document, or regarded as optional, together with details of any incidents occurred when performing the method, which might have influenced the test result(s).EN 16032-2011 pdf download.
EN 16032-2011 pdf download
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