高效液相色谱-电感耦合等离子体-串联质谱法同时测定饲料中As(Ⅲ)、As(Ⅴ)、氨苯胂酸和洛克沙胂

Simultaneous Determination of As(Ⅲ),As(Ⅴ),p-ASA and ROX in Feeds by High Performance Liquid Chromatography-Inductivily Coupled Plasma-Tandem Mass Spectrometry

建立了饲料中As(Ⅲ)、As(Ⅴ)、氨苯胂酸(p-ASA)和洛克沙胂(ROX)不同形态砷的高效液相色谱-电感耦合等离子体-串联质谱(HPLC-ICP-MS/MS)检测方法。样品经甲醇-水(1∶1,V/V)超声提取,用Shiseido MGⅡC18色谱柱(250×4.6 mm,5μm)对4种砷形态进行分离,以pH=4.7的6mmol/L四丁基氢氧化铵(TBAH)-甲醇(92∶8,V/V)溶液及pH=1.9的0.05%三氟乙酸(TFA)-甲醇(92∶8,V/V)溶液为流动相进行梯度洗脱。然后通过电感耦合等离子体质谱进行监测,外标法定量。结果表明,在优化的实验条件下,各形态砷在0~50μg/L范围内线性良好(R≥0.9999),As(Ⅲ)、As(Ⅴ)、氨苯胂酸(p-ASA)和洛克沙胂(ROX)的检测限分别为0.05、0.10、0.08、0.60μg/L,4种形态砷的加标回收率范围在85.9%~104.6%之间,相对标准偏差(RSD)均小于5%。通过对实际样品的检测,该方法适用于饲料中常见形态砷的检测。

A high performance liquid chromatography-inductively coupled plasma-tandem mass spectrometry （HPLC-ICP-MS/MS） was developed for the determination of 4 arsenic species including arsenite（As （Ⅲ））, arsenate（As（V） ）, 4-aminophenylarsonic acid （p-ASA） and roxarsone （ROX） in feeds. The feeds samples were mechanically extracted with 10 mL mixture of methanol（MeOH）-water（l： 1） by ultrasonic method for 1 h at 30 C. Combined supernatant after 9 000 r/min centrifugal for 5 rain, and 5 mL extracting agent（MeOH-water 1＂ 1 ,V/V） were added to residue and put into ultrasound for 30 min. Repeatted the above steps once. The arsenic species in feeds were analyzed on a Shiseido MG 1I C18 （250 X 4. 6 mm, 5 /am） chromatographic column using tetrabutylammonium hydroxide（TBAH） （pH = 4. 7）-MeOH （92 ： 8,V/V） and trifluoroacetic acid （TFA） （pH = 1.9）-MeOH （92＂ 8, V/V） as mobile phase, and then analyzed by HPLC-ICP-MS/MS, quantitatived by external standard method. The results showed a good linearity（R=0. 9999）. The detection limits were 0.05 g/L As（ HI ） ,0.10 g/L As（ V ）, 0.08 g/L（p-ASA） and 0.60 g/L（ROX）, respectively. The spiked recoveries of the four kinds of arsenic species were in the range of 85. 9 %-104.6 % with good RSDs which were less than 5 %. Through the detection of the actual sample, the method was suitable for the detection of some common arsenic species in feeds.