在线固相萃取-液相色谱法测定食品中4种类胡萝卜素含量

Determination of 4 kinds of carotenoids in foodstuffs by online solid phase extraction-liquid chromatography

中文关键词:  胡萝卜素  叶黄素  婴幼儿配方奶粉  天然食品  在线固相萃取

英文关键词:carotene  lutein  zeaxanthin  infant formula milk powder  natural food  online solid phase extraction-liquid chromatography

中文摘要:

      目的 建立在线固相萃取-液相色谱法(online solid phase extraction-liquid chromatography, online SPE-LC)同时测定婴幼儿配方乳粉和天然食品中叶黄素、玉米黄质、α-胡萝卜素和β-胡萝卜素含量的方法。方法 样品采用浓度为50%氢氧化钾溶液在70 ℃下皂化15 min, 皂化液以70%乙醇定容, 高速离心后取上清液直接上机分析。选择聚苯乙烯-二乙烯基苯基质的SelectCore PSS色谱柱作为online SPE柱, 采用80%甲醇-水作为初始上样溶剂, 乙腈/甲基叔丁基醚作为清洗溶剂。采用ChromCore C30 (4.6 mm×250 mm, 3 μm)作为分析柱, 乙腈-甲醇(26:74, V:V, 含0.4 g/L抗坏血酸)与甲基叔丁基醚作为流动相, 梯度洗脱, 流速为1.0 mL/min, 检测波长为450 nm。结果 婴幼儿配方乳粉和天然食品中4个目标物分离良好, 所有目标物的线性相关系数r>0.9999, 叶黄素、玉米黄质及α-胡萝卜素、β-胡萝卜素的方法定量限分别为0.77、0.72、0.94、1.40 μg/100 g, 婴幼儿配方乳粉基质加标平均回收率分别为99.76%、103.51%、99.16%和97.92%; 方法重复性的相对标准偏差小于2.5%。结论 该方法快速、可靠及重复性良好, 可满足食品中叶黄素、玉米黄质和α-胡萝卜素、β-胡萝卜素的定量要求, 可被应用于实际样品的检测中。

英文摘要:

      Objective To develop a method for the simultaneous determination of lutein, zeaxanthin, α-carotene, and β-carotene in infant formula milk powder and natural foods by online solid phase extraction-liquid chromatography (online SPE-LC). Methods Samples were saponified with 50% potassium hydroxide solution at 70 ℃ for 15 min. Saponified solution was diluted with 70% ethanol, and after high-speed centrifugation, the supernatant was directly analyzed. A styrene-divinylbenzene copolymer-based SelectCore PSS-packed chromatographic column was chosen as the online SPE column, using 80% methanol-water as the initial loading solvent and acetonitrile/methyl tert-butyl ether as the washing solvent. A ChromCore C30 column (4.6 mm×250 mm, 3 μm) was used as the analytical column, with acetonitrile-methanol (26:74, V:V, 0.4 g/L of ascorbic acid) and methyl tert-butyl ether as the mobile phase for gradient elution. The flow rate was 1.0 mL/min, and the detection wavelength was 450 nm. Results The 4 target analytes in infant formula milk powder and natural foods were well separated. Linear correlation coefficients for all target analytes were greater than 0.9999. The limit of quantification of method for lutein, zeaxanthin, α-carotene, and β-carotene were 0.77, 0.72, 0.94, and 1.40 μg/100 g, respectively. Average recovery rates of infant formula milk powder were 99.76%, 103.51%, 99.16%, and 97.92%, respectively. The relative standard deviations of method repeatability for all the analytes were less than 2.5%. Conclusion This method is accurate, reliable, and reproducible and can meet the quantitative requirements of lutein, zeaxanthin, and α-carotene, β-carotene in foodstuffs. It can be applied to the determination of real samples.