液相色谱-氢化物发生-原子荧光联用同时测定洛克沙胂及其代谢物

Simultaneous Analysis of Roxarsone and Its Metabolites by Liquid Chromatography-Hydrodide Generation-Atomic Fluorescence Spectrometry

利用液相色谱-氢化物发生-原子荧光联用技术同时检测5种砷形态化合物(亚砷酸、砷酸、一甲基胂酸、二甲基胂酸和洛克沙胂)。结果表明,在梯度洗脱条件下,以C18反相柱作分离柱,含0.5mmol/L四丁基溴化铵的NaH2PO4-CH3OH溶液为流动相,5种砷化合物得以完全分离;以20g/LK2S2O8为氧化剂进行紫外消解,7%HCl为载流,20g/LKBH4为还原剂,砷化合物形成最佳的原子荧光信号。5种砷化合物在一定的浓度范围内与荧光峰面积呈良好的线性关系;检出限<10μg/L;加标回收率为81.4%～105.6%;相对标准偏差RSD<4.0%。本方法适用于饲料、鸡粪、土壤和植物样品中洛克沙胂及其代谢物(亚砷酸、砷酸、一甲基胂酸和二甲基胂酸)的含量分析。

Simultaneous determination of five speciations of arsenic compounds including arsenite,arsenate,monomethylarsonic acid,dimethylarsinic acid,and roxarsone was studied by liquid chromatography-hydrodide generation-atomic flurescence spectrometry.It was showed that five speciation of arsenic compounds could be separated through C18 reversed phase column using NaH2PO4：CH3OH solution containing 0.5 mmol/L tetrabutyl ammonium bromide as mobile phase at the gradient elution condition;Arsenic compounds could form optimal fluorescence signal using 20 g/L K2S2O8 as UV digest oxidant,7% hydrochloric acid as carrying solution and 20 g/L KBH4 solution as reducing agent.A good linear relationship between fluorescence peak area and concentration of five kinds of arsenic compounds in certain range was obtained.The detection limit of arsenic compounds was not more than 10.0 μg/L,recoveries were controlled in the range of 81.4%-105.6% and relative standard deviations less than 4.0%.This method can be applied to analyze the concentration of roxarsone and its metabolites such as arsenite,arsenate,monomethylarsonic acid,dimethylarsinic acid in feed,chicken manure,soil and plant samples.