GB 1903.56-2022 English PDF (GB1903.56-2022)

This document applies to sodium selenite, a food nutritional fortification substance, of which sodium selenite is prepared from selenous acid and sodium hydroxide, and then it is obtained by oxidizing sodium selenite with hydrogen peroxide. 2 Chemical name, molecular formula, structural formula and relative molecular mass 2.1 Chemical name Sodium selenate. 2.2 Molecular formula Na2SeO4 2.3 Structural formula 2.4 Relative molecular mass 188.94 (according to the international relative atomic mass in 2018) 3 Technical requirements 3.1 Sensory requirements Sensory requirements shall meet the requirements in Table 1. GB 1903.56-2022 www.ChineseStandard.net ? Buy True-PDF ? Auto-delivery. Page 4 of 11 Table 1 -- Sensory requirements Item Requirement Inspection method Color White or colorless Take an appropriate amount of sample and put it in a clean and dry white porcelain plate. Under natural light, observe its color and state. State Crystalline powder 3.2 Physical and chemical indicators Physical and chemical indicators shall meet the requirements in Table 2. Table 2 -- Physical and chemical indicators Item Indicator Inspection method Sodium selenate content (on a dry basis), w/% ¡Ý 99.0 A.4 in Annex A Sodium selenite content (dry basis), w/% ¡Ü 0.1 A.4 in Annex A Loss on drying, w/% ¡Ü 0.5 Direct drying method a in GB 5009.3 Lead (Pb)/(mg/kg) ¡Ü 1.0 A.5 in Annex A Total arsenic (as As)/(mg/kg) ¡Ü 5.0 A.5 in Annex A Cadmium (Cd)/(mg/kg) ¡Ü 1.0 A.5 in Annex A Total Mercury (as Hg)/(mg/kg) ¡Ü 1.0 A.5 in Annex A a The sample weight is 10g. GB 1903.56-2022 www.ChineseStandard.net ? Buy True-PDF ? Auto-delivery. Page 5 of 11 Annex A Inspection methods A.1 Warning According to the provisions of Chapter 6 of GB 12268-2012, sodium selenate belongs to item 6.1 toxic substance. Handle with care. Some reagents used in the inspection methods of this Standard are toxic or corrosive. Operate according to relevant national regulations. Use it with caution. If splashed on skin, rinse wi...