高效液相色谱法测定饲料中七种水溶性色素

Simultaneous Determination of 7 Kinds of Water-soluble Pigments in Feeds by High Performance Liquid Chromatography

关键词:  高效液相色谱  水溶性色素  饲料

Key words:  high performance liquid chromatography  water-soluble pigments  feeds

摘要:

应用高效液相色谱法建立了饲料中柠檬黄、桔黄、胭脂红、食品红、苋菜红、亮蓝、靛蓝7种水溶性色素测定的新方法。样品经40 mL乙腈-丙二醇-水-氨水(25:5:19:1)分两次提取,PWAX柱净化处理后,以0.02 mol/L乙酸铵溶液(pH=5.0)-乙腈为流动相进行梯度洗脱,7种水溶性色素经C18柱得到良好分离。7种水溶性色素在0.5(1.0) ~ 50 μg/mL范围内线性关系良好,相关系数均不小于0.999。亮蓝的检出限为0.25 mg/kg,定量限为0.5 mg/kg；柠檬黄、苋菜红、胭脂红、桔黄、食品红的检出限为0.5 mg/kg,定量限为1.0 mg/kg；靛蓝的检出限为1.0 mg/kg,定量限为2.0 mg/kg。饲料样品在定量限、低、中、高4个加标浓度下,7种水溶性色素的回收率为60.6% ～ 116.1%,相对标准偏差为0.9% ~ 7.3%,结果表明方法适用于饲料中7种水溶性色素的检测要求。该方法操作简单、准确、杂质干扰少。

Abstract:

A method based on high performance liquid chromatography was developed for quantitative analysis of 7 kinds of water-soluble pigments in feeds. The conditions of sample preparation and analysis were optimized in this thesis. The pigments were firstly extracted with 40 mL of acetonitrile-propanediol-water-ammonia water (25:5:19:1) by twice and purified by PWAX SPE column. A HPLC separation was carried on an Agilent-C18 column (4.6 mm×250 mm, 5 μm) with the mobile phase of acetonitrile-0.02M ammonium(pH=5.0) for gradient elution and detected using a UV detector at 425 nm,500 nm,630 nm. The method was quantified by the external standard method and the linear ranges for 7 kinds of pigments were in the range of 0.5(1.0) - 50 μg/mL with correlation coefficients greater than 0.999. The average recoveries ranged from 60.6% to 116.1% of 7 kinds of pigments in feeds at four different levels, with RSD less than 7.3% .The limits of detection were 0.25 mg/kg,0.5 mg/kg,1.0 mg/kg and the limits of quantitation were 0.5 mg/kg,1.0 mg/kg,2.0 mg/kg. The results indicated that the method develop was highly sensitive and selective in determination of 7 kinds of water-soluble pigments in feeds.