大米中铬的光度法测定

Spectrophotometric Determination of Chromium in Rice

样品加２５％Ｎａ２ＣＯ３于８００℃马弗炉中灰化分解，铬用二苯胺基脲显色，分光光度法测定．结果表明，大米中铬含量为２９１．５ｎｇｇ－１，相对标准偏差为３．１８％，加标回收率为９８．５％．

The sample was digested with 25% Na 2CO 3 in muffle furnace at 800℃ Cr iorn was coloured by DPC and determined spectrophotometrically.Results show that Cr is 291.5ng·g -1 in rice,and the relative standard deviation was 3.18%.The recovery of chromium was 98.5%.