Song Yi-Zhen, Zhang Xiu-Xiu, Ma Biao, Wu Zhi-Yong, Zhang Zi-Qiang
Research Center for Analytical Sciences, Chemistry Department, College of Sciences, Northeastern University, Shenyang 110819, China.
Research Center for Analytical Sciences, Chemistry Department, College of Sciences, Northeastern University, Shenyang 110819, China.
Anal Chim Acta. 2017 Dec 1;995:85-90. doi: 10.1016/j.aca.2017.09.040. Epub 2017 Oct 17.
Quantification is a fundamental aspect of performance of an analytical system. Paper-based analytical device (PAD) as an on-site detection platform has drawn wide attention mainly due to its portability and cost effectiveness. In this work, a portable and low-cost PAD for online preconcentration and sensitive determination of fluorescent whitening agent (FWA) was demonstrated, which was consisted of ultra violet light-emitting diode (UV LED), macro-focusing lens, smartphone and miniaturized DC voltage source. Taking a widely used FWA component VBL as the analyte, the performance of the PAD enhanced with electrokinetic stacking (ES) and fluorescence imaging detection was systematically investigated. With ES, the sensitivity of the PAD system was 160-fold enhanced, and a limit of detection (LOD) of 0.06 μg mL was achieved. The dynamic range was 0.1-10.0 μg mL (linear in 0.1-0.7 μg mL, R = 0.99). With manual operation, the relative standard deviation (RSD) of intra-day and inter-day were all below 15%. Eventually, VBL from different napkin samples and toilet paper was determined with average recovery rates in the range of 90%-95% (RSD = 8.0%-12.0%). This work shows that with ES, the sensitivity of PAD can be greatly improved, and a LOD close to a desktop fluorescent spectrophotometer can be achieved as demonstrated by the detection of FWA component.
定量分析是分析系统性能的一个基本方面。基于纸的分析装置（PAD）作为一种现场检测平台，因其便携性和成本效益而备受关注。在这项工作中，展示了一种用于在线预富集和灵敏测定荧光增白剂（FWA）的便携式低成本PAD，它由紫外发光二极管（UV LED）、微距聚焦透镜、智能手机和小型直流电压源组成。以一种广泛使用的FWA成分VBL作为分析物，系统研究了采用电动堆积（ES）和荧光成像检测时PAD的性能。通过ES，PAD系统的灵敏度提高了160倍，检测限（LOD）达到0.06 μg/mL。动态范围为0.1 - 10.0 μg/mL（在0.1 - 0.7 μg/mL范围内呈线性，R = 0.99）。手动操作时，日内和日间的相对标准偏差（RSD）均低于15%。最终，测定了不同餐巾纸样品和卫生纸中的VBL，平均回收率在90% - 95%范围内（RSD = 8.0% - 12.0%）。这项工作表明，通过ES，PAD的灵敏度可以大大提高，并且如对FWA成分的检测所示，能够实现接近台式荧光分光光度计的检测限。
