US EPA

3786376 

Journal Article 

Simple mercury speciation analysis by CVG-ICP-MS following TMAH pre-treatment and microwave-assisted digestion 

Wu, Yi; Lee, Y; Wu, Li; Hou, X 

2012 

1 

Microchemical Journal
ISSN: 0026-265X
EISSN: 1095-9149 

103 

105-109 

10.1016/j.microc.2012.01.011 

WOS:000304025200013 

A simple method was proposed for mercury cold vapor generation (CVG) in tetramethylammoniumhydroxide (TMAH) solution for speciation analysis of ultratrace inorganic mercury and total mercury in biological samples by inductively coupled plasma mass spectrometry (ICP-MS). Prior to analysis, 100-300 mg of the biological sample was accurately weighed into a conical tube. Then, 2 mL of 25% (m/v) TMAH solution was added to the sample, incubated at room temperature for several hours (hair, 3 h), and diluted to 25 mL with water. Finally, inorganic mercury was directly determined by CVG-ICP-MS, while microwave-assisted oxidation with H2O2 was needed for total mercury detection. The concentration of organic mercury, mainly methylmercury, was obtained by difference of total mercury and inorganic mercury. Only one calibration curve against mercury aqueous standards in 2% TMAH medium was needed for both procedures. Optimum conditions for mercury CVG, as well as sample preparation and microwave-assisted digestion were investigated in detail. A limit of detection (LOD, 3 sigma) of 3 ng L-1 was obtained and the linear working range was 0.1-100 mu g L-1. Validation data were provided based on the analysis of water samples, as well as a CRM human hair sample (GBW 070601). This is a simple, rapid, ultrasensitive and relatively green method for the determination of mercury in water and biological samples. (C) 2012 Elsevier B.V. All rights reserved. 

ICP-MS; TMAH; Microwave-assisted digestion; Biological samples; Mercury speciation