摘要
本文介绍用塞曼石墨炉原子吸收法直接测定海水样品中的痕量镉。通过实验发现,抗坏血酸和硝酸混和或者酒石酸与硝酸混和使用都可有效地消除海水基体的干扰,考虑到酒石酸较稳定,因此选用酒石酸为基体改进剂。无需灰化而直接原子化。对Z180-80型仪器,原子化温度为700℃,对Z3030型仪器,原子化温度为950℃。仪器用单纯标准溶液校准。通过与极谱法比较及对标准海水样的测定,表明该法准确可靠。
Several organic matrix modifiers have been studied for the elimination of seawater matrixeffects in the determination of Cd by direct graphite furnace atomic absorption spectrometry.Ascorbic acid+ HNO_3 and tartaric+HNO_3 are found to be very efficient. Since tartaric acid ismore stable, it is used in this work for eliminating matrix interferences. Ashing step is notnecessary and the atomising temperature is set at 700°C for Z 180--80 instrument and 950°C forZ 3030 instrument. Simple standards are used for calibrating spectrometer. The accuracy of thedetermination is assessed by a) comparing our result with those obtained by polarographicmethod; b) by analysing the National Seawater Standards. The results are satisfactory.
关键词
GFAAS
海水
镉
测定
酒石酸
Cadmium
seawater
graphite furnace atomic absorption spectrometry
tartaric acid
