Department of Chemistry and Biochemistry, University of Texas at Arlington, Texas, USA.
Food Chem. 2016 Aug 15;205:23-7. doi: 10.1016/j.foodchem.2016.02.118. Epub 2016 Feb 23.
A headspace gas chromatography (HSGC) method was developed for the determination of water content in honey. This method was shown to work with five different honey varieties which had a range of water from 14-16%. It also utilised two different detectors, the thermal conductivity detector (TCD) and the barrier discharge ionisation detector (BID). This method needs no heating pretreatment step as in the current leading method, (i.e. the measurement of refractive index). The solvent-free procedure negates the possibility of solvent-compound interactions as well as solubility limitations, as is common with Karl Fischer titrations. It was also apparent that the classic loss on drying method consistently and substantially produced results that were lower than the correct values. This approach is shown to be rapid, with an analysis time of 4 min when using the TCD detector and under 3 min when utilising the BID detector. HSGC is feasible for the determination of water due to the new PEG-linked geminal dicationic ionic-liquid-coated GC capillary column. In addition it provides accurate and precise determinations of the water content in honey. When using the sensitive BID detector, other trace volatile compounds are observed as well.
建立了一种顶空气相色谱(HSGC)法测定蜂蜜中的水分含量。该方法适用于 5 种不同的蜂蜜品种,水分含量在 14-16%之间。该方法还使用了两种不同的检测器,即热导检测器(TCD)和阻挡放电电离检测器(BID)。与现行主流方法(即折射率测量)不同,该方法无需加热预处理步骤。无溶剂的程序消除了溶剂-化合物相互作用以及溶解度限制的可能性,这在卡尔费休滴定中很常见。显然,经典的干燥失重法始终会产生比实际值低的结果。当使用 TCD 检测器时,该方法的分析时间为 4 分钟,当使用 BID 检测器时,分析时间不到 3 分钟,因此该方法非常快速。HSGC 可用于测定水,因为使用了新的 PEG 连接的双阳离子季铵盐涂层 GC 毛细管柱。此外,它还可以对蜂蜜中的水分含量进行准确、精密的测定。当使用灵敏的 BID 检测器时,还可以观察到其他痕量挥发性化合物。