银离子固相萃取-程序升温大体积进样-气相色谱法定量分析市售巧克力中的饱和烷烃矿物油

发布时间：2018-11-20 16:59

【摘要】：建立了银渍硅胶固相萃取柱离线(Ag-SPE)净化,程序升温进样-气相色谱-氢火焰离子化检测器(PTV-GC-FID)定量分析巧克力中饱和烷烃矿物油(MOSH)的方法。以正己烷浸泡提取巧克力中的MOSH,离心后取1 mL上清液,过0.3%Ag渍硅胶SPE柱净化,氮吹浓缩,定容至0.2 mL,注入GC分析;GC的进样口程序升温过程:初始温度45℃,保持1 min(分流比200∶1),以250℃/min升温至360℃(分流阀关闭2 min),并保持27 min(分流比100∶1);进样量40μL;柱温箱升温程序为:35℃保持3 min,以25℃/min升温至350℃,以5℃/min升温至370℃,保持10 min,载气为高纯氮气,流速1.3 mL/min(压力60 k Pa);FID温度为380℃。结果表明,本方法的MOSH定量限为0.5 mg/kg,加标回收率为84.9%~108.6%,相对标准偏差(RSD)为0.2%~1.5%。运用本方法对25个市售巧克力样品中的MOSH含量进行了测定,3个样品未检出,其余22个样品中MOSH含量为1.09~8.15 mg/kg(其中C_(16)~C_(35)的含量为0.56~4.43 mg/kg),有3个样品含量高于5.00 mg/kg,为严重污染样品。本方法操作简便,检出限低,适用于巧克力中MOSH的定量测定。
[Abstract]:A method for the determination of (MOSH) in saturated alkane mineral oil in chocolate by temperature-programmed injection gas chromatography-hydrogen flame ionization detector (PTV-GC-FID) has been established by using silver silica gel solid phase extraction column off-line (Ag-SPE) purifying and temperature-programmed injection-gas chromatography-hydrogen flame ionization detector (PTV-GC-FID). One mL supernatant was extracted by centrifugation with MOSH, extracted from chocolate with n-hexane immersion. The supernatant was purified by 0.3%Ag silica gel SPE column, then concentrated by nitrogen blow, and then injected into GC at a constant volume of 0.2 mL,. The process of GC injection programmed temperature is as follows: initial temperature 45 鈩，

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