title: Performance Evaluation of an Improved GC-MS Method to Quantify Methylmercury in Fish.
abstract: Here, we set out to improve our previously developed methylmercury analytical method, involving phenyl derivatization and gas chromatography-mass spectrometry (GC-MS). In the improved method, phenylation of methylmercury with sodium tetraphenylborate was carried out in a toluene/water two-phase system, instead of in water alone. The modification enabled derivatization at optimum pH, and the formation of by-products was dramatically reduced. In addition, adsorption of methyl phenyl mercury in the GC system was suppressed by co-injection of PEG200, enabling continuous analysis without loss of sensitivity. The performance of the improved analytical method was independently evaluated by three analysts using certified reference materials and methylmercury-spiked fresh fish samples. The present analytical method was validated as suitable for determination of compliance with the provisional regulation value for methylmercury in fish, set in the Food Sanitation haw.
authors.affiliation: National Institute of Health Sciences.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Watanabe
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kikuchi
authors.forename: Rieko
authors.initials: R
authors.lastname: Matsuda
authors.forename: Tomoko
authors.initials: T
authors.lastname: Hayashi
authors.forename: Koichi
authors.initials: K
authors.lastname: Akaki
authors.forename: Reiko
authors.initials: R
authors.lastname: Teshima
mesh_terms: D000818:Animals; D001881:Borates / Q000032:analysis; D005396:Fish Products / Q000032:analysis; D005399:Fishes; D005504:Food Analysis / Q000379:methods*; D005506:Food Contamination / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D008767:Methylmercury Compounds / Q000032:analysis*; D014050:Toluene; D014867:Water
chemical_list: D001881:Borates; D008767:Methylmercury Compounds; C489231:sodium tetrapropylborate; D014867:Water; D014050:Toluene