Karadjova I, Venelinov T
Faculty of Chemistry, University of Sofia, J. Bourchier 1, 1126 Sofia, Bulgaria.
Food Addit Contam. 2002 Oct;19(10):948-53. doi: 10.1080/02652030210155387.
A simple and fast method for the determination of arsenic (As) in sunflower oil by electrothermal atomic absorption (ETAAS) is described. The optimal instrumental parameters for ETAAS measurement of As species in stable and homogeneous soap emulsions prepared from oil samples with tetramethylammonium hydroxide (TMAH) have been established. The limit of determination is 5 ng x g(-1) total As in sunflower oil. A second approach involving extraction of As and mercury from sunflower oil and consequent ETAAS measurement is also described. Simultaneous quantitative extraction of As(III), As(V), monomethylarsonate (MMA) and dimethylarsinate (DMA) as well as Hg(II), monomethylmercury(II)chloride (MMC), dimethylmercury (DMM), diethylmercury (DEM) and diphenylmercury (DPM) is achieved by using an extraction mixture comprising of 0.1M NH3/0.01 M EDTA. Pre-reduced palladium is applied as an effective modifier for the next ETAAS measurement of all extracted species. The method of standard addition is employed for calibration. The accuracy and reproducibly of the methods was established by spike and recovery experiments and parallel analysis of sunflower oils from the marketplace. Limits of determination of 2 ng x g(-1) for As and 3 ng x g(-1) for mercury were obtained.
本文描述了一种用电热原子吸收光谱法（ETAAS）测定葵花籽油中砷（As）的简单快速方法。已确定了在由油样与氢氧化四甲铵（TMAH）制备的稳定均匀肥皂乳液中，用ETAAS测量砷物种的最佳仪器参数。葵花籽油中总砷的测定限为5 ng x g(-1)。还描述了另一种方法，即从葵花籽油中萃取砷和汞，随后进行ETAAS测量。通过使用由0.1M NH3/0.01M EDTA组成的萃取混合物，可同时定量萃取As(III)、As(V)、一甲基砷酸（MMA）和二甲基砷酸（DMA）以及Hg(II)、氯化一甲基汞（MMC）、二甲基汞（DMM）、二乙基汞（DEM）和二苯基汞（DPM）。预还原钯用作所有萃取物种后续ETAAS测量的有效改性剂。采用标准加入法进行校准。通过加标回收实验及对市售葵花籽油的平行分析，确定了方法的准确性和重现性。砷的测定限为2 ng x g(-1)，汞的测定限为3 ng x g(-1)。
