Comparison of different derivatization approaches for mercury speciation in biological tissues by gas chromatography/inductively coupled plasma mass spectrometry
✍ Scribed by Garc�a Fern�ndez, Rub�n; Montes Bay�n, Mar�a; Garc�a Alonso, J. Ignacio; Sanz-Medel, Alfredo
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 108 KB
- Volume
- 35
- Category
- Article
- ISSN
- 1076-5174
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✦ Synopsis
A novel interface design for coupling gas chromatography and inductively coupled plasma mass spectrometry (GC/ICP-MS) was used to perform mercury speciation in biological tissues. Three derivatization approaches were optimized and compared for this purpose: anhydrous butylation using a Grignard reagent, aqueous ethylation by means of NaEt 4 B and aqueous propylation with NaPr 4 B. The last reagent was synthesized in the laboratory as it is not commercially available. Detection limits obtained by GC/ICP-MS ranged between 100 and 200 fg (as absolute mass) for methylmercury and between 500 and 600 fg for inorganic mercury using a 1 µl injection. Quantification of methyl-and inorganic mercury was carried out by resorting to aqueous calibration, using ethylmercury as internal standard for both propylation and butylation derivatization techniques. For ethylation procedures, a methylpropylmercury solution was used as internal standard. The absence of transmethylation during sample preparation was checked using a 97% enriched 202 Hg inorganic standard. The accuracy of the three derivatization approaches was evaluated by the analysis of the certified reference material DOLT-2 (dogfish liver) from the National Research Council of Canada and certified for methylmercury, with satisfactory results.