EDTA络合滴定法测定彩钢板中锌层质量

Determination of Zinc Layer Quality in Color Steel by EDTA Complexation Titration

采用EDTA络合滴定法测定彩钢板中锌的含量。制取一块50mm×40mm大小的彩钢板,经无水乙醇浸泡处理后,用游标卡尺量取其镀锌面长宽尺寸,用50m L的盐酸缓释溶液进行溶解,溶解完毕后过滤定容至100m L,摇匀;吸取母液25m L于三角瓶中,加水后滴加(1+1)氨水溶液至母液p H值在8左右,加10m L氨-氯化铵缓冲溶液,5m L三乙醇胺和5滴铬黑T指示剂,用EDTA溶液测定至变色计数,计算其锌层质量;通过对溶解酸和缓蚀效率试验,其结果符合国家标准要求;用3个自制样品进行测定精密度和对比实验(n=10),其RSD%在0.5%以内,对比试验符合要求。

The content of zinc in color steel was determined by EDTA eomplexation titration.. Preparation of a color steel plate of 50mm × 40mm size, soaked through ethanol, using vernier caliper to measure its length and width of the galvanized surface, dissolved with hydrochloride sustained - release 50mL solution, dissolved after filtration volume to 100mL, 25mL to shake flask; draw the mother liquor after adding water, （ 1 ＋ 1 ） ammonia solution to mother liquor pH at around 8, plus 10mL ammonia ammonium chloride buffer solution, 5mL triethanolamine and 5 drops of chrome black T indicator, EDTA solution is used to calculate the measured color count, zinc layer quality; through test and inhibition efficiency on the dissolution of acid, the results accord with the requirements of the national standard; Determination of precision and comparative experiments with 3 homemade samples （ n = 10）, the RSD% is less than 0.5%, to meet the requirements of comparative test.