Pojjanapornpun Siriluck, Aryusuk Kornkanok, Lilitchan Supathra, Krisnangkura Kanit
Division of Biochemical Technology, School of Bioresources and Technology, King Mongkut's University of Technology Thonburi (Bangkhuntien), 49 Tien Thale 25 Bangkhuntien-Chai Thale Rd., Thakham, Bangkok, 10150, Thailand.
Department of Nutrition, Faculty of Public Health, Mahidol University, 420/1 Ratchawithi Rd., Rachathewi, Bangkok, 10400, Thailand.
Anal Bioanal Chem. 2017 Apr;409(11):2777-2789. doi: 10.1007/s00216-017-0222-0. Epub 2017 Feb 6.
The Gibbs energy additivity method was used to correlate the retention time (t ) of common fatty acid methyl esters (FAMEs) to their chemical structures. The t of 20 standard FAMEs eluted from three capillary columns of different polarities (ZB-WAXplus, BPX70, and SLB-IL111) under both isothermal gas chromatography and temperature-programmed gas chromatography (TPGC) conditions were accurately predicted. Also, the predicted t of FAMEs prepared from flowering pak choi seed oil obtained by multistep TPGC with the BPX70 column were within 1.0% of the experimental t . The predicted t or mathematical t (t ) values could possibly be used as references in identification of common FAMEs. Hence, FAMEs prepared from horse mussel and fish oil capsules were chromatographed on the BPX70 and ZB-WAXplus columns in single-step and multistep TPGC. Identification was done by comparison of t with the t of standard FAMEs and with t . Both showed correct identifications. The proposed model has six numeric constants. Five of six could be directly transferred to other columns of the same stationary phase. The first numeric constant (a), which contained the column phase ratio, could also be transferred with the adjustment of the column phase ratio to the actual phase ratio of the transferred column. Additionally, the numeric constants could be transferred across laboratories, with similar correction of the first numeric constant. The TPGC t predicted with the transferred column constants were in good agreement with the reported experimental t of FAMEs. Moreover, hexane was used in place of the conventional t marker in the calculation. Hence, the experimental methods were much simplified and practically feasible. The proposed method for using t as the references would provide an alternative to the uses of real FAMEs as the references. It is simple and rapid and with good accuracy compared with the use of experimental t as references.
采用吉布斯能量加和法将常见脂肪酸甲酯（FAMEs）的保留时间（t ）与其化学结构相关联。准确预测了在等温气相色谱和程序升温气相色谱（TPGC）条件下，从三根不同极性的毛细管柱（ZB-WAXplus、BPX70和SLB-IL111）上洗脱的20种标准FAMEs的t 。此外，用BPX70柱通过多步TPGC从开花小白菜籽油中制备的FAMEs的预测t 与实验t 的偏差在1.0%以内。预测的t 或数学t （t ）值可能用作鉴定常见FAMEs的参考。因此，对从贻贝和鱼油胶囊中制备的FAMEs在BPX70和ZB-WAXplus柱上进行了单步和多步TPGC色谱分析。通过将t 与标准FAMEs的t 以及t 进行比较来进行鉴定。两者均显示鉴定正确。所提出的模型有六个数值常数。六个常数中的五个可以直接转移到相同固定相的其他柱上。包含柱相比的第一个数值常数（a），也可以在将柱相比调整为转移柱的实际相比后进行转移。此外，数值常数可以跨实验室转移，对第一个数值常数进行类似的校正。用转移后的柱常数预测的TPGC t 与报道的FAMEs实验t 吻合良好。此外，在计算中用己烷代替了传统的t 标记物。因此，实验方法大大简化且切实可行。所提出的以t 作为参考的方法将为使用真实FAMEs作为参考提供一种替代方法。与使用实验t 作为参考相比，它简单快速且准确性高。
