砷的光度法测定一般都沿用经典的DDTC-Ag法和砷钼蓝法。前者显色稳定,准确度高,但操作繁复,费时,吸收液有毒;后者灵敏度高,但不够稳定。本文研究了砷钼酸-碱性染料在聚乙烯醇存在下测砷的方法,着重对甲基紫、乙基紫、结晶紫、孔雀绿、亮绿等三苯甲烷类及罗丹明B碱性染 Spectrophotometric determination of arsenic generally follow the classic DDTC-Ag method and arsenic molybdenum blue method. The former color stability, high accuracy, but the operation complicated, time-consuming, toxic liquid absorption; the latter high sensitivity, but not stable enough. In this paper, arsenic molybdic acid - basic dye in the presence of polyvinyl alcohol in the presence of arsenic detection methods, focusing on methyl violet, ethyl violet, crystal violet, malachite green, bright green and other benzene and rhodamine B alkaline dye