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目的建立冰淇淋和雪糕中硫氰酸盐的离子色谱测定方法。方法将样品融化混匀,用乙腈沉淀蛋白,上层样液在4℃下冷冻离心后,取上清液用固相萃取On GuardⅡRP柱过滤后超滤离心,超滤液直接用离子色谱仪进行测定。采用Ion PacAS16型分析柱进行分离,用ASRS-ULTRAⅡ型阴离子抑制器、KOH淋洗液进行梯度洗脱,ED50型电导检测器进行检测,以外标法定量。结果硫氰酸盐的标准曲线在0.10 mg/L~2.0 mg/L时呈现良好的线性关系,其线性方程为y=0.192x-0.015,相关系数r=0.999 2。该方法得到的硫氰酸盐的检出限为0.30 mg/kg,定量限为0.99 mg/kg,回收率为94.5%~103.6%,相对标准偏差RSD为1.4%~2.6%。结论本方法样品前处理的净化效果好,准确可靠,适用于冰淇淋和雪糕中硫氰酸盐的检测。
Objective To establish a method for the determination of thiocyanate in ice cream and ice cream by ion chromatography. Methods The samples were thawed and mixed, the protein was precipitated with acetonitrile, the supernatant was frozen and centrifuged at 4 ° C, the supernatant was filtered on On Guard Ⅱ RP column and centrifuged. The ultrafiltrate was determined by ion chromatography . Using Ion Pac AS16 analytical column for separation, with ASRS-ULTRA 型 anion suppressor, KOH elution gradient elution, ED50 conductivity detector for detection, external standard. Results The standard curve of thiocyanate showed a good linearity at 0.10 mg / L ~ 2.0 mg / L with a linear equation of y = 0.192 × -0.015 and a correlation coefficient of 0.999 2. The detection limit of thiocyanate was 0.30 mg / kg, the limit of quantification was 0.99 mg / kg, the recovery was 94.5% ~ 103.6%, and the relative standard deviation (RSD) was 1.4% ~ 2.6%. Conclusion The pretreatment of this method has a good purification effect, accurate and reliable, and is suitable for the detection of thiocyanate in ice cream and ice cream.