title: Ionic liquid as a mobile phase additive in high-performance liquid chromatography for the simultaneous determination of eleven fluorescent whitening agents in paper materials.
abstract: In the present study, 11 4,4'-diaminostilbene-2,2'-disulfonic acid based fluorescent whitening agents with different numbers of sulfonic acid groups were separated by using an ionic liquid as a mobile phase additive in high-performance liquid chromatography with fluorescence detection. The effects of ionic liquid concentration, pH of mobile phase B, and composition of mobile phase A on the separation of fluorescent whitening agents were systematically investigated. The ionic liquid tetrabutylammonium tetrafluoroborate is superior to tetrabutylammomnium bromide for the separation of the fluorescent whitening agents. The optimal separation conditions were an ionic liquid concentration at 8 mM and the pH of mobile phase B at 8.5 with methanol as mobile phase A. The established method exhibited low limits of detection (0.04-0.07 ng/mL) and wide linearity ranges (0.30-20 ng/mL) with high linear correlation coefficients from 0.9994 to 0.9998. The optimized procedure was applied to analyze target analytes in paper samples with satisfactory results. Eleven target analytes were quantified, and the recoveries of spiked paper samples were in the range of 85-105% with the relative standard deviations from 2.1 to 5.1%. The obtained results indicated that the method was efficient for detection of 11 fluorescent whitening agents.
authors: The college of pharmacy and the key laboratory of cardio-cerebrovascular natural drug research of Hunan province, Xiangnan university, Hunan, China.
authors: Qing
authors: Q
authors: Wang
authors: Chenzhou city center for disease control and prevention, Hunan, China.
authors: Xianbo
authors: X
authors: Chen
authors: Chenzhou city center for disease control and prevention, Hunan, China.
authors: Bin
authors: B
authors: Qiu
authors: Chenzhou city center for disease control and prevention, Hunan, China.
authors: Liang
authors: L
authors: Zhou
authors: The college of pharmacy and the key laboratory of cardio-cerebrovascular natural drug research of Hunan province, Xiangnan university, Hunan, China.
authors: Hui
authors: H
authors: Zhang
authors: The college of pharmacy and the key laboratory of cardio-cerebrovascular natural drug research of Hunan province, Xiangnan university, Hunan, China.
authors: Juan
authors: J
authors: Xie
authors: The college of pharmacy and the key laboratory of cardio-cerebrovascular natural drug research of Hunan province, Xiangnan university, Hunan, China.
authors: Yan
authors: Y
authors: Luo
authors: The college of pharmacy and the key laboratory of cardio-cerebrovascular natural drug research of Hunan province, Xiangnan university, Hunan, China.
authors: Bin
authors: B
authors: Wang
keywords: Fluorescent whitening agents; Ionic liquids; Liquid chromatography; Separation mechanisms