CAJ | 학술논문

海水溶解无机碳(DIC)的平均浓度约为2.05mmol/L,其中HCO3-占93%, CO32-为6%,CO2和H2CO3共1%.HCO3-的拉曼散射活性太弱,而其他成分的浓度又过低,使得海水中DIC组分不能产生明显的拉曼散射强度,目前还未见有关溶解无机碳拉曼光谱定量分析的报道.为突破这一局限,本研究探索了一种碱化辅助的拉曼定量分析方法,以海水DIC中拉曼活性最低、占比例最大的HCO3-为研究对象进行了可行性实验研究.通过碱化处理(100mL样品中添加NaOH试剂15mg)将HCO3-转化为拉曼活性更强的CO32-,有效提高了拉曼光谱系统对HCO3-的检出限(<3mmol/L).定量分析使用内标定法,选取水在~1635cm-1附近的 O-H 弯曲振动谱带作为标定物.实验结果显示,该方法对与海水中浓度相当的低浓度HCO3-溶液的定量分析具有良好的精度(相对误差<6.5%).
해수용해무궤탄(DIC)적평균농도약위2.05mmol/L,기중HCO3-점93%, CO32-위6%,CO2화H2CO3공1%.HCO3-적랍만산사활성태약,이기타성분적농도우과저,사득해수중DIC조분불능산생명현적랍만산사강도,목전환미견유관용해무궤탄랍만광보정량분석적보도.위돌파저일국한,본연구탐색료일충감화보조적랍만정량분석방법,이해수DIC중랍만활성최저、점비례최대적HCO3-위연구대상진행료가행성실험연구.통과감화처리(100mL양품중첨가NaOH시제15mg)장HCO3-전화위랍만활성경강적CO32-,유효제고료랍만광보계통대HCO3-적검출한(<3mmol/L).정량분석사용내표정법,선취수재~1635cm-1부근적 O-H 만곡진동보대작위표정물.실험결과현시,해방법대여해수중농도상당적저농도HCO3-용액적정량분석구유량호적정도(상대오차<6.5%).
The mean concentration of dissolved inorganic carbon(DIC) in seawater is about 2.05mmol/L. Approximately 93%of DIC is HCO3-, 6%is CO32-, and only 1%is CO2 and H2CO3. Since Raman activity of HCO3-is weak and the concentration of other species is low, it is impossible for DIC in seawater to generate Raman scattering that is intense enough to be detected. There is no report on quantitative analysis of DIC in seawater using Laser Raman Spectrometry so far. In order to break through the limitation, a Raman spectroscopy quantitative analysis method assisted with sample alkalization was proposed. HCO3-was treated as study object because it takes the largest share and the Raman activity of it was the weakest among all DIC species. The solution was alkalized to convert HCO3-into CO32-which was more Raman active. OH bending band of water was treated as the internal standard for its stability. The Raman spectroscopy analysis detecting limit of HCO3-was increased, and the quantitative analysis result showed good accuracy (relative error<6.5%).