GB/T 17776-2016Determination of sulfur in feedstuff - Magnesium nitrate method (English PDF)

Foreword

This standard is drafted in accordance with the rules given in GB/T 1.1-2009. This standard replaces GB/T 17776-1999 "Determination of sulfur in feed by magnesium nitrate". The main technical content of this standard and GB/T 17776-1999 difference is as follows:

1 Scope" added "the standard limit of 0.20%";

--- "4 reagents and solutions" in the warning language "Warning

--- magnesium nitrate flammable, explosive, irritating, storage should be away from the light, away from the fire Species, heat, to avoid direct contact with the human body. ";

--- in the "7 measurement steps" under the heading "warning

--- magnesium nitrate flammable, explosive, irritating, heating must be small fire, cautious operating. "; In the original standard "

7 Determination step" "Remove the porcelain crucible, after cooling, add 15mL water, 7mL hydrochloric acid (4.1), boil, Filtered, washed thoroughly, and the filtrate was diluted to about.200 mL. "Revised to"

7 Determination Procedure "" Remove the porcelain crucible, pending After cooling, add 15 mL of water, 7 mL of hydrochloric acid (4.1), boil, filter and wash the residue with hot distilled water every 10 mL ~ 20 mL Until the filtrate is about.200mL. " This standard is proposed and assigned by the National Committee for Standardization of Feed Industry (SAC/TC76). The drafting of this standard unit. the State Feed Quality Supervision and Inspection Center (Wuhan). The main drafters of this standard. Qian Fang, Huang Ting, He Xu Kong, Wang Sisi, Gao Junfeng, Zhang Yong, Yang Lin, He Fengqin. This standard replaced the previous version of the standard release.

--- GB/T 17776-1999. Determination of sulfur in feed Magnesium nitrate method

1 Scope

GB/T 17776-2016 is the Chinese national standard on determination of sulfur in feedstuff - magnesium nitrate method, in the field of agriculture. The /T suffix marks it as a recommended standard: it is not compulsory by itself, but it becomes binding as soon as a contract, a tender or a customer specification calls it up - which in practice is how most foreign buyers meet it. It was issued on 14 June 2016 by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China; Standardization Administration of China, and has been in force since 1 January 2017. Classification: ICS 65.120, CCS B46. This page is published from the official record of the standard held by the Chinese standards administration: the identification, the dates, the classification and the issuing body are taken from there. The clause text, the tables and the numeric limits are in the document itself, which is delivered complete in English translation.

This standard specifies the determination of sulfur in feed. This standard applies to a single feed, with feed, concentrated feed and concentrate supplement. The standard limit is 0.20%.

2 Normative reference documents

The following documents are indispensable for the application of this document. For dated references, only the dated edition applies to this article Pieces. For undated references, the latest edition (including all modifications) applies to this document.

GB/T 6682 Analytical laboratory water specifications and test methods

GB/T 14699.1 Feed Sampling GB/T .20195 Preparation of animal feed samples

3 Principle

The sulfur in the feed sample was fixed with magnesium nitrate to complete the oxidation. Under acidic conditions, sulfate ions are precipitated as sulfuric acid with barium chloride Barium, precipitated by filtration, washing and burning, weighing barium sulfate in order to obtain sulfur content.

4 Reagents and solutions

Warning - magnesium nitrate flammable, explosive, irritating, storage should be away from light, away from fire, heat, to avoid direct contact with the human body. Unless otherwise specified, all reagents used in this standard are of analytical grade. Experimental water should be consistent with GB/T 6682 in the three water specifications or quite pure Degree of water.

4.1 Hydrochloric acid.

4.2 magnesium nitrate solution. Weigh 95g of magnesium nitrate [Mg (NO3) 2 · 6H2O] dissolved in water and diluted to 100mL.

4.3 barium chloride solution. 10g barium chloride dissolved in 100mL water.

4.4 silver nitrate solution. concentration c (AgNO3) 0.1mol/L.

5 Instruments and equipment

In addition to commonly used laboratory equipment, other equipment as follows:

5.1 Sampling. pore size of 0.42mm (40 mesh).

5.2 Analysis of the balance. the sense of 0.0001g.

5.3 high temperature furnace. controllable temperature at 820 °C ± 20 °C.

5.4 porcelain crucible. 50mL.

5.5 thermostat electric furnace.