A method was developed for the determination of residual glycerides in biodiesel on the basis of thin layer chromatography-thermally assisted hydrolysis and methylation-gas chromatography (TLC-THM-GC) using a pyrolysis-GC system. With the THM in the presence of an organic alkali, trimethylsulfonium hydroxide (TMSH), glycerides were converted into their corresponding fatty acid methyl esters. Thus, residual glycerides could be determined well by the total peak area of fatty acid methyl esters formed. Glycerides in samples were separated by TLC, and then were extracted. The results showed that by adding 3 μL TMSH (0. 1 mol/L) methanol solution to 3 μL extract of sample and methylating the mixture at 350 °C , the glycerides would be sensitively determined. The calibration curves of monoglyceride, diglyceride and triglyceride exhibited good linearity with the regression coefficients from 0. 9863 to 0. 9993 at the concentration ranged from 60 to 2000 mg/L. The reproduc-ibility was fairly good with the RSD (n = 5) from 3. 2% to 7. 2% for four kinds of diglycerides at 250 mg/L concentration level. The potential of the proposed method was assessed by applying it to the determination of residual glyceride in biodiesel. The results prove this TLC-THM-GC technique is an accurate and sensitive method for determining residual glyceride in biodiesel samples.%建立了薄层色谱-热辅助水解甲基化-气相色谱法测定生物柴油中残余甘油酯含量的方法.样品中的甘油酯经薄层色谱分离,萃取后与三甲基氢氧化硫(0.1 mol/L)各3 μL先后加入到样品杯中,在350℃下,于裂解器中进行衍生化反应,气相色谱测定生成的脂肪酸甲酯,确定甘油酯的含量.生物柴油中常见的甘油一酯、二酯、三酯在60～2000 mg/L浓度范围内线性关系良好,r2为0.9863～0.9993.对于浓度为250 mg/L的4种甘油二酯重复测定5次,相对标准偏差为3.2％～7.2％.本方法对实际样品中的甘油酯的测定结果表明,方法准确、灵敏.
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