HPLC-ICP-MS联用测定食用菌中的Cr(Ⅲ)和Cr(Ⅵ)

Determination of Cr(Ⅲ) and Cr(Ⅵ) in Edible Fungi by High Performance Liquid Chromatography with Inductively Coupled Plasma Mass Spectrometry

采用磷酸缓冲溶液(0.5mol/L K_2HPO_4和0.5mol/L KH_2PO_4混合溶液)及碱性提取液(0.5mol/L NaOH和0.28mol/L Na_2CO_3混合溶液)提取食用菌中的三价铬[Cr(Ⅲ)]和六价铬[Cr(Ⅵ)],用高效液相色谱分离,电感耦合等离子体质谱仪测定,建立了食用菌中Cr(Ⅲ)和Cr(Ⅵ)的高效液相色谱-电感耦合等离子体质谱(HPLC-ICP-MS)检测方法。方法学考察结果表明,该方法在0.4~20μg/L浓度范围内呈良好线性关系(R2>0.999);Cr(Ⅲ)和Cr(Ⅵ)的方法检出限为0.03mg/kg,定量限为0.10mg/kg;精密度(RSD<5%)、重复性(RSD<10%)良好;回收率为81%~101%,该方法可满足多种食用菌鲜样和干样中Cr(Ⅲ)和Cr(Ⅵ)的测定。

A method for determination of trivalent chromium [Cr（ Ⅲ ）] and hexavalent chromium [Cr（ VI ）] in edible fungi was established using high performance liquid chromatography with inductively coupled plasma mass spectrometry （HPLC-ICP-MS）. Cr（ Ⅲ ） and Cr（VI） were first extracted using a phosphate buffer solution （0.5 mol/L Ke HPO4 ＆ 0.5 mol/L KH2 PO4 ） and an alkaline extraction solution （0.5 mol/L NaOH ＆ 0.28 mol/L Na2CO3）, and then analyzed by HPLC-ICP-MS. The results showed that the calibration curves for Cr（Ill） and Cr （Ⅵ） were linear in the concentration range of 0.4--20 μg /L and the correlation coefficients were 0. 9998 for both Cr（ Ⅲ） and Cr（VI ）. The limit of determination （LOD） for Cr （Ill） and Cr （VI） were 0.03 mg, and the limit of quantification （LOQ） for Cr（Ⅲ） and Cr（VI） were 0.10 mg. The recoveries of Cr（ Ⅲ ） and Cr（ VI ） ranged from 81% to 102% with relative standard deviations lower than 10%. This method is sensitive, efficient, reliable, and can be used for the determination of Cr（ Ill ） and Cr （VI） in both fresh and dried edible fungi samples.