Ng J H, Tan B
Department of Chemistry, University of Massachusetts, Amherst 01003.
J Chromatogr Sci. 1988 Sep;26(9):463-9. doi: 10.1093/chromsci/26.9.463.
Palm oil carotenoids are analyzed by nonaqueous reversed-phase high-performance liquid chromatography (NARP-HPLC) with UV/vis diode-array detection. Isocratic elution with 60% acetonitrile/35% methanol/5% methylene chloride at 2 mL/min on a 25-cm C18 column results in an analysis time of 30 min. Identification is made through absorption spectra and chromatographic elution behaviors, for example, polyenic pi conjugation, dipole moment of end-groups, and oxygen function on the chromophores. At least 12 carotenoids are identified with alpha- and beta-carotene as the dominant carotenoids (1:2 ratio). Several mono- and di-epoxides of alpha- and beta-isomers and hydrocarbon carotenes are found, including the UV-absorbing phytoene identified by spectral substraction. cis-Isomerization is found and discussed in the light of spectral evidence. The effect of saponification time on the amount of extracted carotenes is investigated. Quantitation results in a combined alpha- and beta-carotene concentration of at least 506 ppm. The detection limit for beta-carotene is 31 ng.
采用非水反相高效液相色谱法（NARP-HPLC）并结合紫外/可见二极管阵列检测对棕榈油中的类胡萝卜素进行分析。在一根25厘米的C18柱上，以2毫升/分钟的流速用60%乙腈/35%甲醇/5%二氯甲烷进行等度洗脱，分析时间为30分钟。通过吸收光谱和色谱洗脱行为进行鉴定，例如多烯π共轭、端基的偶极矩以及发色团上的氧官能团。至少鉴定出12种类胡萝卜素，其中α-胡萝卜素和β-胡萝卜素为主要类胡萝卜素（比例为1:2）。发现了α-和β-异构体的几种单环氧化物和二环氧化物以及烃类胡萝卜素，包括通过光谱减法鉴定出的具有紫外吸收的八氢番茄红素。根据光谱证据发现并讨论了顺式异构化现象。研究了皂化时间对类胡萝卜素提取量的影响。定量结果显示α-胡萝卜素和β-胡萝卜素的总浓度至少为506 ppm。β-胡萝卜素的检测限为31纳克。
