在线样品前处理大体积进样离子色谱法直接测定海水中亚硝酸盐、硝酸盐和磷酸盐  

Direct determination of nitrites,nitrates and phosphates in seawater using suppressed conductivity ion chromatography with large volume injection and on-line sample preparation techniques

作　　者：林红梅[1,2] 林奇[1,2] 张远辉[1,2] 张静静[3] 陈立奇[1,2] 

机构地区：[1]国家海洋局第三海洋研究所,福建厦门361005 [2]国家海洋局海洋-大气化学与全球变化重点实验室,福建厦门361005 [3]厦门大学海洋与地球学院,福建厦门361005

出　　处：《色谱》2012年第4期374-377,共4页Chinese Journal of Chromatography

基　　金：国家海洋局第三海洋研究所基本科研业务费专项资金项目(海三科2008002);中国极地科学战略研究基金项目(20080222)

摘　　要：采用戴安公司谱睿(Pre)在线样品除氯技术,结合OnGuard Ba柱去除硫酸盐,建立了离子色谱直接测定海水中亚硝酸盐、硝酸盐和磷酸盐的方法。该方法以IonPac AG23为富集柱,高容量IonPac AS23为分离柱,淋洗液自动发生装置在线产生KOH溶液进行梯度淋洗,抑制电导检测。实验结果表明:样品稀释5～10倍时,直接进样不会干扰目标物测定。当流速为1 mL/min、进样量为500μL时,海水中NO2--N、NO3--N、PO34--P的方法检出限分别为0.3、0.4、0.2μg/L,线性范围分别为10～500μg/L、14～680μg/L、3.4～170μg/L,线性相关系数r均大于0.999 0。测得人工海水样品中目标物的加标回收率为92%～106%,相对标准偏差(RSD,n=6)为1.2%～7.7%。该方法一次进样可在13 min内完成分析,具有操作简单快捷、无污染等优点,能满足近海海水中NO2-、NO3-、PO34-的定量分析要求。Using on-line pre-chlorine and sulfate removal technique,a rapid and direct method was established for the simultaneous determination of nitrite-N,nitrate-N and phosphate-P in seawater by ion chromatography（IC） with suppressed conductivity detection.In this method,an IonPac AG23 column was used as the enrichment column,an IonPac AS23 column with high capacity as the analytical column,and KOH solution as the eluent for gradient elution produced by an eluent generator on-line automatically.The results showed that the determination of the targets was not interfered when a seawater sample diluted 5 to 10 times was directly injected.The method detection limits（MDL） of nitrite-N,nitrate-N and phosphate-P were 0.3,0.4 and 0.2 μg/L respectively,under the conditions of 500 μL sample volume and 1 mL/min elution rate.The linear ranges of nitrite-N,nitrate-N and phosphate-P were 10-500 μg/L,14-680 μg/L and 3.4-170 μg/L respectively,and the correlation coefficients（r） were all greater than 0.999 0.The average recoveries of the 3 analytes spiked in a sample ranged from 92% to 106% with the relative standard deviations（RSDs,n=6） of 1.2%-7.7%.The whole sample analysis process can be completed in 13 min.The method has the advantage of simple operation,reagent-free and pollution-free,and can meet the quantitative analysis requirements of seawater.

关 键 词：在线样品前处理技术 大体积进样 离子色谱 亚硝酸盐 硝酸盐 磷酸盐 海水 

分 类 号：O658[理学—分析化学]