- P-ISSN 1225-0163
- E-ISSN 2288-8985
추출한 유기상 속의 희토류 원소를 유도결합 플라스마 질량분석법(inductively coupled plasma mass spectrometry, ICP-MS)으로 정량하는 방법에 대하여 연구하였다. 희토류 원소를 추출한 유기상의 과다한 도입을 방지하기 위하여 탈용매화장치를 장착한 초음파 분무기를 이용하여 ICP-MS에 주입하였다. 에탄올(EtOH)에 MIBK(methyl isobutyl ketone)를 섞은 용매를 도입하였을때, 계수율(count rate)이 증가하였고, 여기에 0.03 M의 추출제 HEH(2-ethylhexyl-2-ethylhexyl phosphonic acid, P507, PC88A)를 섞었을 때는 감소하였다. 탈용매화장치의 냉각장치(condenser)의 최적온도는 -10 <TEX>$^{\circ}C$</TEX>이었고, 가열관(heating tube)의 최적온도는 150 <TEX>$^{\circ}C$</TEX>이었다. 계수율이 최대이고, 반사파(reflect power)가 최소인 최적 운반기체의 흐름속도는 0.7 L/min이었다. MIBK에 추출제 HEH가 0.03 M이 섞여있는 추출용매로 추출을 행하였을 때, 최적 pH는 4.3이었고, 추출시간은 10 분이었다. 최적조건에서 0.2 <TEX>${\sim}$</TEX> 20 ng/mL의 표준용액으로 얻은 검정곡선으로부터 구한 검출 한계는 0.02 <TEX>${\sim}$</TEX> 0.05 ng/mL 이었다.
Analytical method to determine rare earth elements which were extracted to organic phase by inductively coupled plasma mass spectrometry(ICP-MS) was investigated. Organic phase which had extracted rare earth elements was directly aspirated into ICP-MS by ultrasonic nebulizer(USN) in order to reduce solvent load to the plasma. Then, the count rate increased when MIBK(methyl isobutyl ketone) was added to EtOH(ethanol) but decreased when 0.03 M HEH(2-ethylhexyl-2-ethylhexyl phosphonic acid, <TEX>$P_{507}$</TEX>, PC88A) was added to solvent which mixed MIBK with EtOH. The optimal temperatures of desolvation system were -10 <TEX>$^{\circ}C$</TEX> for the condenser and 150 <TEX>$^{\circ}C$</TEX> for the heating tube. The optimal nebulizer flow rate which gave maximum count rate and minimum reflect power was 0.7 L/min. The optimal pH and extraction time were 4.3 and 10 min for MIBK-0.03 M HEH system. Detection limits which were obtained through calibration curves at the range of 0.2 <TEX>${\sim}$</TEX> 20 ng/mL were 0.02 <TEX>${\sim}$</TEX> 0.05 ng/mL under the optimal experimental conditions.