State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, Zhejiang, P. R. China.
Food Testing Laboratory, Ningbo Customs Technology Center, Ningbo, P. R. China.
J Sep Sci. 2021 Jan;44(2):539-548. doi: 10.1002/jssc.202000902. Epub 2020 Dec 13.
Carotenoids consist of a series of conjugated isoprene units that are characteristically highly conjugated through double bonds, leading to the formation of many isomers that are susceptible to oxidation and other chemical modifications. Extreme hydrophobicity and high complexity make carotenoids difficult to identify and quantify. We implemented the use of a common Syncronis C18 column with strong eluting solvent, here isopropanol, to successfully separate a mixture of 23 carotenoids standards with different structural properties. In addition, the method differentiated between three groups of isomeric carotenoids (lycopene/δ-carotene/γ-carotene/ε-carotene/α-carotene/β-carotene, α-cryptoxanthin/β-cryptoxanthin, and zeaxanthin/lutein) by optimizing the gradient profile and using liquid chrmatography-mass spectrometry. The LOD ranged from 0.05 to 5.51 ng/mL, and the recovery of carotenoids in Mytilus coruscus was from 63.54 to 93.25%, with standard deviations <10%. Twenty-five carotenoids were detected with a total content of 857 ± 55.1 mg/kg, and three isomeric carotenoids were identified: ε-carotene, α-carotene, and β-carotene. Our results show that this methodology is a significant improvement over other alternatives for analyzing carotenoids because of its compatibility with carotenoids of different categories, and most importantly, its ability to resolve isomeric carotenes, which is significant not only for assessing carotenoid species, but also for the tracing of metabolic pathways of carotenoids.
类胡萝卜素由一系列共轭异戊二烯单元组成，这些单元通过双键高度共轭，形成许多易氧化和其他化学修饰的异构体。极强的疏水性和高度复杂性使得类胡萝卜素难以识别和定量。我们采用了常见的 Syncronis C18 柱和强洗脱溶剂异丙醇，成功分离了 23 种具有不同结构特性的类胡萝卜素标准品混合物。此外，该方法通过优化梯度曲线和使用液相色谱-质谱法，区分了三组异构体类胡萝卜素（番茄红素/δ-胡萝卜素/γ-胡萝卜素/ε-胡萝卜素/α-胡萝卜素/β-胡萝卜素、α-隐黄质/β-隐黄质和玉米黄质/叶黄素）。检测限范围为 0.05 至 5.51 ng/mL，贻贝中类胡萝卜素的回收率为 63.54 至 93.25%，标准偏差 <10%。共检测到 25 种类胡萝卜素，总含量为 857 ± 55.1 mg/kg，鉴定出 3 种异构体类胡萝卜素：ε-胡萝卜素、α-胡萝卜素和 β-胡萝卜素。我们的结果表明，与其他分析类胡萝卜素的方法相比，该方法具有显著的优势，因为它适用于不同类别的类胡萝卜素，最重要的是，它能够解析异构体类胡萝卜素，这不仅对评估类胡萝卜素种类具有重要意义，而且对类胡萝卜素代谢途径的追踪也具有重要意义。
