GC测定不同蛋类及不同烹饪方法鸡蛋蛋黄中胆固醇的含量

Gas Chromatography Determination of Cholesterol Content of Different Kinds and Different Cooking Methods of Eggs in Yolk

目的:建立气相色谱法测定不同禽类蛋蛋黄中胆固醇含量的方法,并对不同烹饪方法鸡蛋中胆固醇的含量进行比较。方法:2.0 mol·L-1的氢氧化钾-乙醇溶液水浴皂化,石油醚萃取后采用气相色谱法分析检测。柱程序升温:200℃保持4min,以12℃·min-1升至300℃,保持10 min;进样口温度260℃,FID检测器温度:300℃;氮气流速30 mL·min-1,氢气流速47 mL·min-1,空气流速400 mL·min-1。结果:胆固醇在20 min内检出,胆固醇在1.2～7.2μg线性关系良好(r=0.999 4。该方法的精密度(RSD=0.16%),重复性(RSD=2.5%)良好;加样回收率在100.24%～103.89%;不同禽类蛋中,胆固醇含量为:土鸡蛋>普通鸡蛋>鸭蛋,本鸡蛋,鹌鹑蛋(三者差异不大);并比较了不同烹饪方法鸡蛋中胆固醇含量,结果为白煮蛋>鸡蛋>茶叶蛋。结论:气相色谱法作为蛋黄中胆固醇含量的快速测定方法,具有试剂用量少,操作简单,结果准确、可靠,重复性良好等特点。

Objective： To establish a gas chromatography method for the determination of cholesterol content in different kinds egg yolk; and comparing study on cholesterol content in the yolks by different cooking methods was made in the article. Method： Saponification bath with 2.0 mol L-1 KOH-EtOH, using gas chromatography determination after petroleum ether extraction. Column temperature program ： maintaining at 200℃ for 4 rain, up to 300℃ by 12 ℃.min-1, keeping 10 min. Injector temperature 260℃; FID detector temperature was 300℃ ; nitrogen flow rate was 30 mL.min-1 ; hydrogen flow rate was 47 mL.min-1 ; air flow rate： 400 mL.min-1. Result： Cholesterol checked within 20 min, linear relationship was good within the range of 1.2-7.2 μg （r =0. 999 4）. The precision （RSD 0. 16% ） and repeatability （RSD 2.5% ） of this method was good and the recovery was between 97.53% -101.92%. Cholesterol content of different eggs： local eggs 〉 normal eggs 〉 duck eggs, general eggs, quail eggs （little difference between the three） ; the results of cholesterol content by comparing different cooking methods of eggs was： boiled eggs 〉 normal eggs 〉 tea eggs. Conclusion： Gas chromatography as a rapid method for cholesterol content determination in egg yolk has characteritics as small amount of reagent, easy operation and accurate resuhs etc.