CAJ | 학술논문

以蒸馏法为基础,研究了适合海水中铵盐稳定氮同位素分析的预处理方法。对蒸馏法预处理过程中的最佳蒸馏时间、沸石的选取、铵盐最适浓度范围等分别进行改进和优化,获得稳定、高效的海水中铵盐氮稳定同位素分析预处理方法。结果表明：最佳蒸馏时间为50 min,铵盐的回收率为(97±5.8)%。测定了不同沸石对不同浓度氨氮的吸附率,筛选出酸性条件下铵氮吸附效率较高且稳定的康华科技沸石；确定铵盐的最佳适用浓度范围为2~10μmol/L,在该浓度范围内氮回收率94%~99%,氮分馏系数为0.1‰~0.8‰。将此方法应用于长江口海域水样分析,结果表明,这一方法可以应用于河口中铵盐的氮同位素分析,能够为河口中溶解态氮的来源及循环机理等研究提供有效信息。
이증류법위기출,연구료괄합해수중안염은정담동위소분석적예처리방법。대증류법예처리과정중적최가증류시간、비석적선취、안염최괄농도범위등분별진행개진화우화,획득은정、고효적해수중안염담은정동위소분석예처리방법。결과표명：최가증류시간위50 min,안염적회수솔위(97±5.8)%。측정료불동비석대불동농도안담적흡부솔,사선출산성조건하안담흡부효솔교고차은정적강화과기비석；학정안염적최가괄용농도범위위2~10μmol/L,재해농도범위내담회수솔94%~99%,담분류계수위0.1‰~0.8‰。장차방법응용우장강구해역수양분석,결과표명,저일방법가이응용우하구중안염적담동위소분석,능구위하구중용해태담적래원급순배궤리등연구제공유효신식。
A pretreatment method was developed for determination of nitrogen isotopic composition in ammonium based on the rapid steam distillation method. Ammonium was enriched by distillation in alkaline environment and collected on zeolite. The stable nitrogen isotope ratio in dissolved ammonium was obtained by detecting the filtered and dried zeolite. The optimal distillation time, appropriate zeolite, and optimal concentration range of NH4Cl were characterized. The optimal distillation time was 50 min and the average recovery of samples was (97±5.8)%. The optimality zeolite was determined by measurement of the adsorption efficiency of different zeolites under acid con-ditions. The optimal concentrations of ammonium was 2~10μmol/L with a ammonium recovery rate of 94%~100%, and the isotopic fractionation was 0.1‰~0.8‰. This method was successfully applied to samples collected from the Changjiang River estuary. The method is suitable forδ15N analysis of dissolved ammonium in seawaters, and could provide valuable information about the source and cycle mechanism of dissolved nitrogen in estuary waters.