氢化物发生-原子荧光法测定植物油中微量砷初探

Research on HG-AFS Determination of Trace Arsenic in Vegetable Oil

摘要:

本方法研究了氢化物—原子荧光光谱法对植物油中微量砷的测定。样品采用四段程序升温灰化减少了砷损失，使用2% HCI作载流，15 g/L KBH4作还原剂。探讨了酸介质、盐酸浓度、硼氢化钾浓度、灯电流等对测定砷荧光强度的影响以及共存离子的干扰，确定了仪器的最佳条件。在试验条件下，本法检出限为0.04 µg/L，在0.0~35.0 µg/L的范围内线性良好，相关系数为0.9998，样品加标回收率为85.3%~95.5%，标准使用液相对偏差为0.57%~1.20%，标准物质相对偏差为4.87%~5.12%。该方法简便、快速、灵敏度高。

Abstract:

The trace amount of arsenic (As) in vegetable oil was determined by hydride generation atomic fluorescence spectrometry method (HG-AFS). The programmable temperature ashing of samples could avoid the As loss. 2 % HCI and 15 g/L KBH4 were used as acid medium and reducing agent, respectively. The effects of some factors on the fluorescence intensity of arsenic, such as acid medium, HCl concentration, the amount of KBH4, the lamp electricity, etc., were investigated and optimized. Within the As content range of 0.0~35.0 g/L, a linear calibration curve for arsenic was obtained and the correlative coefficient and detection limit were of 0.9998 and 0.04 µg/L, respectively. Besides, the recovery rates, the RSDs of the standard solution and standards were found to be 85.3%~95.5%, 0.57%~1.20% and 4.87%~5.12%, respectively. The method was simple, fast and with high sensitivity, which could be applied to the analysis of trace amounts of arsenic in vegetable oil.