Moh F M, Tang T S
Palm Oil Research Institute of Malaysia, Kajang, Selangor, Malaysia.
J AOAC Int. 1999 Jul-Aug;82(4):893-6.
A rapid and direct liquid chromatographic (LC) technique is described for the determination of a eutectic mixture of diphenyl oxide and biphenyl such as Dowtherm A thermal heating fluid (THF) in oleochemicals and palm olein. Analysis is performed with an RP-18 column with fluorescence detection (excitation at 247 nm and emission at 310 nm). The isocratic mobile phase (1.0 mL/min) consists of methanol and water (90 + 10, v/v). A linear calibration model (correlation coefficient = 0.9999) was developed directly from used Dowtherm A THF with the biphenyl peak (4.70 min) as a marker. Average recoveries from spiked glycerin, fatty alcohol mixture, methyl ester mixture, fatty acids, and palm olein were 90.9-108.7%, with a detection limit of 0.1 microgram/mL. The technique requires no prior sample cleanup nor extraction steps and is good for quality assurance purposes.
描述了一种快速直接的液相色谱（LC）技术，用于测定油化学制品和棕榈油精中诸如道氏热载体A热载液（THF）之类的二苯醚和联苯的低共熔混合物。使用RP - 18柱并通过荧光检测（激发波长为247 nm，发射波长为310 nm）进行分析。等度流动相（1.0 mL/分钟）由甲醇和水（90 + 10，v/v）组成。直接以用过的道氏热载体A THF为基础，以联苯峰（4.70分钟）为标记物建立了线性校准模型（相关系数 = 0.9999）。加标甘油、脂肪醇混合物、甲酯混合物、脂肪酸和棕榈油精的平均回收率为90.9 - 108.7%，检测限为0.1微克/毫升。该技术无需事先进行样品净化或提取步骤，适用于质量保证目的。
