Department of Analytical Chemistry, Institute of Chemistry, Faculty of Science, University of Pavol Jozef Šafárik in Košice, Moyzesova 11, 040 01, Košice, Slovak Republic.
Department of Analytical Chemistry, Oles Honchar Dnipro National University, Gagarin Avenue 72, 49010, Dnipro, Ukraine.
Anal Methods. 2022 Sep 1;14(34):3299-3306. doi: 10.1039/d2ay00943a.
A new approach of headspace liquid-phase microextraction with an optical probe (HS-LPME-OP), which solves the problem of the extraction phase retention in the hole of the optical probe and provides the possibility of simpler, more precise and reliable online processing of the analytical signal, was used for sulfite determination. A 1 × 10 M 5,5'-dithiobis-(2-nitrobenzoic) acid (DTNB) solution was used as an acceptor phase. It was placed in a plastic vial fixed in the headspace above the analyte solution. An optical probe immersed in the acceptor phase was used to monitor the analytical signal. Sulfite determination is based on the release of sulfur dioxide from the sample after the addition of -phosphoric acid, followed by its extraction with an aqueous solution of DTNB at pH 7.0. The absorbance was measured at 412 nm. The calibration graph was linear in the range from 32 to 320 μg L with a detection limit of 14 μg L. The developed method is sensitive, highly selective and reproducible. It was successfully applied for the sulfite determination in juice, alcoholic beverages and jam.
一种新的带有光学探头的顶空液相微萃取方法（HS-LPME-OP）被用于亚硫酸盐的测定，该方法解决了萃取相在光学探头孔中保留的问题，并为更简单、更精确和更可靠的在线分析信号处理提供了可能性。实验采用 1×10M5,5′-二硫代双（2-硝基苯甲酸）（DTNB）溶液作为接受相，将其置于固定在分析物溶液上方顶空的塑料小瓶中。一个浸在接受相中的光学探头被用来监测分析信号。在加入-磷酸后，样品中二氧化硫释放，然后在 pH 值为 7.0 的条件下用 DTNB 的水溶液萃取，在 412nm 处测定吸光度。校准曲线在 32 至 320μg/L 范围内呈线性，检出限为 14μg/L。所建立的方法灵敏、选择性高、重现性好。该方法成功地应用于果汁、酒精饮料和果酱中亚硫酸盐的测定。
