建立了硝酸提取,高效液相色谱-原子荧光联用技术测定方便面中不同砷形态的分析方法。样品经0.15 mol/L盐酸溶液超声提取后离心过滤,上机测试。实验表明:砷的4种形态亚砷酸[As(Ⅲ)]、砷酸[As(V)]、一甲基胂酸(MMA)和二甲基胂酸(DMA)的线性范围为0~50μg/L,相关系数(r)均优于0.9990,检出限在2~8μg/L之间,砷各形态的测量重复性(以RSD表示)均小于5%,样品的加标回收率为78%~118%。同时用原子荧光光度计检测了样品中总砷,并将两种方法测定结果进行了对比,结果符合理论以及文献报道。该方法操作简单快速、结果准确可靠,适用于方便面中砷形态的分析测定。
It was proposed an analytical method which utilized nitric acid extraction,high performance liquid chromatography(HPLC) and atomic fluorescence techniques,in order to measure the arsenic speciation in instant noodles. The specimen was extracted using ultrasound and filtered using centrifuge after treated by hydrochloric acid(0.15 mol/L). Results indicated that the linear range of four different speciation[As(Ⅲ),As(V),MMA,DMA] were from 0-50μg/L. The correlation coefficient(r) was more than 0.999 0. The detection limit ranged from 2 to 8μg/L. The measurement repeatability(represented as RSD) was less than 5%. The recovery of the specimen was 78%-118%. This result was compared with total arsenic measured using atomic fluorescence spectrophotometer,which indicated a good coincidence with the theory and reference reports. This method is simple,fast and accurate,which can be used in the measurement of arsenic speciation in the instant noodles.