SPE-HPLC法测定辣椒及其制品中苏丹红色素含量

Detection of Sudan red colorants contents in chilli and pepper-based products by SPE-HPLC

目的建立一种检测辣椒及其制品中4种苏丹红色素(Ⅰ、Ⅱ、Ⅲ、Ⅳ)的固相萃取-高效液相色谱方法。方法样品用正己烷溶解或提取,经Brockman Act.Ⅰ中性氧化铝萃取柱吸附后,以正己烷和丙酮洗涤净化,10%丙酮的水溶液洗脱,将洗脱液浓缩至干,加乙腈溶解并定容。用Merck Lichropher ODS C18分离柱(250 mm×4.6 mm,5μm)分离,以乙腈-水溶液为流动相,采用梯度洗脱,二极管阵列检测器(DAD)定性定量测定辣椒制品中的4种苏丹红色素。结果采用本固相萃取法,10%丙酮的水溶液8 ml即可将苏丹红色素洗脱完全;本法色谱条件简单,480 nm检测波长下,色谱峰分离效果好,线性范围为0.1 mg/L^50 mg/L和0.2 mg/L^50 mg/L,最低检出限(信噪比S/N=3)分别为0.011 mg/kg、0.011 mg/kg、0.009 mg/kg、0.012 mg/kg。在添加量为2μg^5μg时,4种苏丹红色素的回收率为86.71%~95.35%,相对标准偏差(RSD)为0.66%~3.85%。结论本方法经实际应用表明,简便快速、灵敏、准确、可操作性强,具有良好的稳定性和重现性。

Objective To develop a method for detecting 4 kinds of Sudan colorants （Sudan I , Sudan Ⅱ , Sudan Ⅲ, Sudan Ⅳ ） in chilli powder and pepper - based products by solid phase extraction and high performance liquid chromatography（ SPE - HPLC）. Methods Samples were dissolved in hexane or extracted, and absorbed with a neutral alumina extraction column by Brockman Act. I, using hexane and acetone for washing and purifying, to elute with water solution of 10% acetone, the eluate was concentrated to dryness, and were dissolved with acetonitrile for constant volume. The Merck Lichropher ODS C_18 （250 mm ×4.6 mm, 5 μm） was used as chromatographic column for the separation of the four colorants. The conditions of HPLC were as follows, the mobile phase was acetonitrile -water; elntion gradient was selected; diode array detector was used to quantify and determine the four Sudan colorants. Results 4 kinds of Sudan colorants can be eluted easily with 8 ml 10% aque- ous solution of acetone in the used SPE conditions. The chromatograph condictions of this method were simple. The chromato- graph peak separation effect was good at the detection wavelength of 480 rim. The hnear ranges were O. 1 mg/L - 50 mg/L or 0.2 mg/L -50 mg/L, the minimum detection limit （S/N =3） of four colorants was 0.011 mg/kg, 0.011 mg/kg, 0.009 mg/kg, 0.012 mg/kg respectively. The rates of recovery was from 86.71% to 95.35% and the RSD was from 0.66% to 3.85%. Con- clusion The method has the advantage of simplicity, efficiency and repeatability. It is sensitive and precise for the detection of four Sudan colorants and was adaptive to the laboratory determination conditions.