1 Scope
This standard specifies method for analysis of various hygienic indexes of unprocessed grain and processed grain.
This standard is applicable to the analysis of the hygienic indexes of malathion, phorate, fenitrothion, fenthion, DDVP, dimethoate, parathion, phosphide, cyanide, chloropicrin, carbon disulfide, arsenic, mercury, HCH, DDT, aflatoxin B1, cadmium, fluorine, stramonium seed, ergot, ethylene dibromide, heptachlor, aldrin, dieldrin, etc. in unprocessed grain and processed grain.
2 Normative References
The following normative documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments (excluding corrections), or revisions, of any of these publications do not apply to this standard. However parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies.
GB/T 5009.11 Determination of Total Arsenic and Abio-arsenic in Food
GB/T 5009.15 Determination of Cadmium in Foods
GB/T 5009.17 Determination of Total Mercury and Organic-mercury in Foods
GB/T 5009.18 Determination of Fluorine in Foods
GB/T 5009.19 Determination of HCH and DDT Residues in Foods
GB/T 5009.20 Determination of Organophosphorous Pesticide Residues in Foods
GB/T 5009.22 Determination of Aflatoxin B1 in Foods
3 Organoleptic Inspection
The grains shall possess color, luster and smell as that of the normal ones, without mould and deterioration.
4 Physical and Chemical Inspection
4.1 Malathion
4.1.1 Gas chromatography
Operate according to GB/T 5009.20.
4.1.2 Cu-complex compound colorimetry
4.1.2.1 Theory
Extract the malathion with organic solvent, hydrolyze it with sodium hydroxide during which process dimethyl phosphorodithioate is generated to react with copper salt to generate yellow complex. Carry out quantative determination by comparing with standard series.
In this method, the detection limit is 1.25 mg/kg if the sampling amount is 20g.
Foreword i
1 Scope
2 Normative References
3 Organoleptic Inspection
4 Physical and Chemical Inspection