본 연구에서는 물속 As(III)와 As(V)의 종 규명분석에 필요한 HPLC와 DRC-ICP-MS의 최적조건을 설정하고, 이를 이용하여 한강 팔당수계 10개 지류 천으로부터 채취한 시료중의 As(III)와 As(V)를 분석 검토하였다. 종 분리를 위한 HPLC의 이동상으로는 10 mM ammonium nitrate와 10 mM ammonium phosphate monobasic을 사용하였으며, flushing solvent로는 5% v/v 메탄올을 사용하였다. 검출기는 DRC-ICP-MS를, 반응기체는 산소를 사용하였다. 최적 분석조건을 설정하기 위하여 이동상의 pH, 유량 및 시료 주입량과 DRC의 산소 유량을 달리하여 검토한 결과, 이동상의 pH는 9.4, 유량은 1.5 mL/min, 시료 주입량은 100 $mu$L, 산소의 유량은 0.5 mL/min이었을 때 가장 좋은 분석조건으로 나타났다. 검정곡선은 As(III)와 As(V)에 대해 모두 r$^2$ = 0.998 이상의 선형성을 나타냈으며, As(III)의 검출한계는 0.10 $mu$g/L, 정확도(RSD)는 4.3%, 회수율은 95.2%, As(V)의 검출한계는 0.08 $mu$g/L, 정확도(RSD)는 3.6%, 회수율은 96.4%로 나타났다. 분석시간은 4분이었다. 설정된 파라미터를 적용하여 한강 팔당수계 유입 10개 지류 천에서 채수한 시료를 분석한 결과, As(III)는 0.10$sim$0.22 $mu$g/L, As(V)는 0.44$sim$1.19 $mu$g/L의 범위로 나타났으며, 총 비소의 93.5%가 As(V)의 형태인 것을 확인할 수 있었다.
In this study, a technique of speciation and determination of the trace inorganic arsenic(As(III) and As(V)) in water sample using HPLC-DRC-ICP-MS has been developed. Isocratic mobile phase of 10 mM ammonium nitrate and 10 mM ammonium phosphate monobasic was used and methanol(5 v/v%) was used as flushing solvent. Selection of the best flow rate of reaction gas, O$_2$, and optimization of the parameters such as pH and flow rate of mobile phase, and injection volume of sample for the separation and detection of arsenic species were carried out. The oxygen flow rate of 0.5 mL/min, pH of 9.4 and flow rate of 1.5 mL/min of mobile phase, and injection volume of sample of 100 $mu$L were found to be the best parameters for the speciation and determination of arsenic species. The analytical features of the method were detection limit 0.10 and 0.08 $mu$g/L, precision(RSD) 4.3% and 3.6%, and recovery 95.2% and 96.4% for As(III) and As(V), respectively. Analysis time was 4 minutes per sample. Linear calibration graphs with r$^2$ = 0.998 were obtained for both As(III) and As(V). Speciation analysis of arsenic species in the raw water samples collected from the tributary streams to Han River and main stream of Paldnag were performed by the proposed method. The concentrations of As(III) ranged from 0.10 to 0.22 $mu$g/L and As(V) concentrations ranged from 0.44 to 1.19 $mu$g/L, and 93.5% of total arsenic was found to be As(V).
