Choengchan Nathawut, Poontong Bangerdsuk, Mathaweesansurn Arjnarong, Maneerat Noppadol, Motomizu Shoji, Ratanawimarnwong Nuanlaor, Nacapricha Duangjai
Flow Innovation-Research for Science and Technology Laboratories (FIRST Labs).
Applied Analytical Chemistry Research Unit, Department of Chemistry, Faculty of Science, King Mongkut's Institute of Technology Ladkrabang.
Anal Sci. 2018;34(2):169-175. doi: 10.2116/analsci.34.169.
A new design of membraneless gas-diffusion unit with dual acceptor channels for separation, collection and simultaneous determination of two volatile analytes in liquid sample is presented. The unit is comprised of three parallel channels in a closed module. A sample is aspirated into the central channel and two kinds of reagents are introduced into the other two channels. Two analytes are isolated from the sample matrix by diffusion into head-space and absorbed into the specific reagents. Non-absorbed vapor is released by opening the programmable controlled lid. The unit was applied to liquors for measurement of ethanol and acetaldehyde using reverse flow injection. Dichromate and nitroprusside were exploited as reagents for colorimetric detection of ethanol and acetaldehyde, respectively. Good linearity ranges (r >0.99) with high precision (RSD <2%) and high accuracy (recovery: 90 - 105%) were achieved. The results were compared to the results by GC-FID and no significant difference was observed by paired t-test (95% confidence).
本文介绍了一种新型无膜气体扩散装置，该装置具有双受体通道，用于分离、收集和同时测定液体样品中的两种挥发性分析物。该装置由一个封闭模块中的三个平行通道组成。样品被吸入中央通道，两种试剂被引入其他两个通道。两种分析物通过扩散进入顶空从样品基质中分离出来，并被吸收到特定试剂中。通过打开可编程控制的盖子释放未吸收的蒸汽。该装置应用于酒类中乙醇和乙醛的测量，采用逆流注射法。分别使用重铬酸盐和硝普钠作为试剂比色检测乙醇和乙醛。实现了良好的线性范围（r>0.99），具有高精度（RSD<2%）和高准确度（回收率：90-105%）。将结果与气相色谱-火焰离子化检测器（GC-FID）的结果进行比较，配对t检验（95%置信度）未观察到显著差异。
