Evaluation techniques coupled to mass spectrometry (ICP-MS) aimed at the fractionation and chemical speciation of mercury in blood and plasma

Author(s)

Jairo Lisboa Rodrigues

• Document type: Doctoral Thesis
• Press: Ribeirão Preto.
• Institution: Universidade de São Paulo (USP). Faculdade de Ciências Farmacêuticas de Ribeirão Preto (PCARP/BC)
• Defense date: 2010-08-12

Examining board members

Fernando Barbosa Junior; Jose Roberto Ferreira; Pedro Orival Luccas; Antonio Cardozo dos Santos

• Advisor: Fernando Barbosa Junior

Abstract

Mercury (Hg) is one of the most toxic environmental pollutants. It exists primarily in three forms: elemental mercury (Hg0), or metallic mercury, inorganic mercury (Hg-i), particularly mercuric chloride and organic mercury (Hg-o), mainly represented by methylmercury (MeHg) and ethylmercury (EtHg), and the organic forms of mercury are more toxic than the inorganic ones. Then, it is very important the development of simple and fast methods for mercury fractionation (T-Hg, Hg-i and Hg-o by the difference) or speciation (Hg-i, MeHg, EtHg) in biological samples. Then, the aims of this work were to evaluate three analytical methods for: i) mercury fractionation in blood/plasma samples (Hg-t, Hg-i and Hg-o by difference) by using a ICP-MS on line coupled to a cold-vapor generation system (CV ICP-MS), ii) Hg speciation in blood and plasma by using LC coupled to ICP-MS; iii) Hg speciation in blood samples with the use of GC coupled to ICP-MS. For the fractionation method, samples were previously incubated with tetramethylammonium hydroxide (TMAH) at room temperature. On the other hand, for the speciation of Hg in blood/plasma by using HPLC-ICP-MS the extraction of Hg species was carried out with the use of ultrasonic energy. For the speciation methodology with GC-ICP-MS the extraction of Hg species was carried out with the use of microwave-assisted extraction. Validation of the proposed methods were evaluated based on the analysis of the SRM NIST 966 and ordinary blood samples collected from riparians living in the Brazilian Amazon exposed to mercury. In general the proposed methodologies proved to be simple, fast and easily applied in routine analysis by clinical laboratories. (AU)