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目的采用Ionpac AS19色谱柱,建立一种大体积进样,电导检测乳制品中硫氰酸根的梯度淋洗离子色谱法。方法样品加入乙腈沉淀蛋白,冷冻离心,上清液通过RP柱去脂肪,经0.22μm微孔滤膜净化后直接进样。结果低浓度样品检测方法的线性范围0.025~0.50 mg/L,r=0.9999;高浓度样品检测方法的线性范围0.50~5.0 mg/L,r=0.9996。相对标准偏差0.25%~3.40%,平均加标回收率91.3%~97.6%。方法的检出限为0.003 mg/L(0.06 mg/kg),定量限为0.01 mg/L(0.20 mg/kg)。结论该方法灵敏度好、检出限低,适用于乳与乳制品中硫氰酸根含量的测定。
Objective To establish a large volume injection and conductance gradient ion chromatography of thiocyanate in dairy products by Ionpac AS19 column. Methods The samples were precipitated with acetonitrile, frozen and centrifuged. The supernatant was passed through a RP column to remove fat, and then directly injected through a 0.22 μm microporous membrane filter. Results The linear range of low concentration sample detection method was 0.025-0.50 mg / L, r = 0.9999. The linear range of high concentration sample detection method was 0.50-5.0 mg / L, r = 0.9996. The relative standard deviations (RSDs) ranged from 0.25% to 3.40% with an average recovery of 91.3% -97.6%. The limit of detection was 0.003 mg / L (0.06 mg / kg) and the limit of quantification was 0.01 mg / L (0.20 mg / kg). Conclusion The method has good sensitivity and low detection limit. It is suitable for the determination of thiocyanate content in milk and dairy products.