고성능액체크로마토그래피-유도결합플라즈마 질량분석기를 이용한 어류 중 메틸수은 분석법 확립

BACKGROUND: Methylmercury is analyzed by HPLC-ICP/MS because of the simplicity for sample preparation and interference. However, most of the pre-treatment methods for methylmercury need a further pH adjustment of the extracted solution and removal of organic matter for HPLC. The purpose of this study was to establish a rapid and accurate analytical method for determination of methylmercury in fish by using HPLC-ICP/MS. METHOD AND RESULTS: We conducted an experiment for pre-treatment and instrument conditions and analytical method verification. Pre-treatment condition was established with aqueous 1% L-cysteine·HCl and heated at 60℃ in microwave for 20 min. Methylmercury in 50 μL of filtered extract was separated by a C18 column and aqueous 0.1% L-cysteine·HCl + 0.1% L-cysteine mobile phase at 25℃. The presence of cysteine in mobile phase and sample solution was essential to eliminate adsorption, peak tailing and memory effect problems. Correlation coefficient(r2) for the linearity was 0.9998. The limits of detection and quantitation for this method were 0.15 and 0.45 μg/kg respectively. CONCLUSION: Result for analytical method verification, accuracy and repeatability of the analytes were in good agreement with the certified reference materials values of methylmercury at a 95% confidence level. The advantage of the established method is that the extracted solution can be directly injected into the HPLC column without additional processes and the memory effect of mercury in the ICP-MS can be eliminated.