Point Discharge Optical Emission Spectrometer as a Gas Chromatography (GC) Detector for Speciation Analysis of Mercury in Human Hair

Abstract

Speciation analysis of mercury in hair facilitates accurate evaluation of mercury exposure to humans and insights into the intertransformation of different mercury species in the human body. However, conventional hyphenated techniques used for mercury speciation analysis usually require expensive instruments and a complex interface. In this work, a compact and miniaturized point discharge (PD) atomic emission spectrometer was utilized as a detector of gas chromatography for the speciation analysis of mercury. Mercury species extracted from hair were derivatized to their volatile species with NaBEt and subsequently preconcentrated by headspace solid-phase microextraction (HS-SPME) prior to their speciation analysis. Under the optimized conditions, limits of detection of 0.35 μg kg (0.035 ng) and 1.0 μg kg (0.10 ng) were obtained for IHg and MeHg, respectively, with a relative standard deviation (RSD) of better than 3.5%. Because of the compact and miniature conformation, high excitation capability, low power consumption of PD-OES, and efficient preconcentration of mercury species by HS-SPME, the proposed system not only overcomes the shortcomings associated with the conventional hyphenated techniques but also provides several unique advantages, including significant simplification of experimental setup, reduction of dead volume, and improvement of sensitivity. The accuracy of this system was validated by speciation analysis of mercury in a Certified Reference Material (GBW09101b, human hair) and 10 human hair samples collected from different people in the population.

Sensitive Mercury Speciation Analysis in Water by High-Performance Liquid Chromatography-Atomic Fluorescence Spectrometry Coupling with Solid-Phase Extraction

“…There have been many efforts devoted to detect mercury species, such as gas chromatography (GC), 4 high performance liquid chromatography (HPLC), 5 gas chromatography-mass spectrometry (GC-MS), 6 and capillary electrophoresis (CE). 7 However, GC and GC-MS technologies require derivatization, which is commonly considered time-consuming and laborious, while HPLC and CE present low sensitivity.…”

Speciation Analysis of Trace Arsenic, Mercury, Selenium and Antimony in Environmental and Biological Samples Based on Hyphenated Techniques

“…For example, headspace SPME coupled to miniaturized microplasma OES was developed by Zheng et al [57] for the detection of mercury and lead in water samples. It is noted that SPME is also often used as a pretreatment method to separate or preconcentrate analytes prior to chromatographic separation [58,59]. Of course, direct coupling of SPME with particular detectors is also developed.…”

Rapid Screening Analysis of Methylmercury in Fish Samples Using Stannous Chloride Reduction and Direct Sampling Electrothermal Vaporization Atomic Absorption Spectrometry

“…At present, most mercury speciation analysis in fish samples is performed using gas chromatography (GC) 3,4 or GC mass spectrometry (MS), 5 liquid chromatography (LC) [6][7][8] coupled with atomic fluorescence spectrometry (AFS), 9,10 cold vapor atomic absorption spectrometry (CVAAS), 11 and inductively coupled plasma optical emission spectrometry (ICP-OES) 12 or inductively coupled plasma mass spectrometry (ICP-MS). 13 To ensure that the Hg species are not altered during sample preparation, some moderate sample pre-treatments 14 have always been utilized before chromatographic separation, including shaking and ultrasonic extraction using mild extractants, such as acid/alkali solutions with or without organic reagents.…”