DOI: 10.3724/SP.J.1140.2013.06173

Marine Geology & Quaternary Geology (海洋地质与第四纪地质杂志) 2013/33:6 PP.173-177


This paper presents a simple and rapid method to concentrate ammonium and nitrate from freshwater samples for an on-line isotope analysis using an elemental analyzer coupled to a mass spectrometer.Ammonium and nitrate are collected by passing the water-sample through pre-filled,disposable,ion exchanging resin columns.The ammonium and nitrate in sample solutions are separated as ammonium into diluted H2SO4by sequential distillation techniques.Then,the excrescent SO2-4in the distillate is precipitated directly as an insoluble salt of BaSO4.(NH4)2SO4is collected by freezing-drying filtrate,which is subsequently combusted in an elemental analyzer forδ15 N determination.The sorption efficiency of 001×7cationic resin and 732cationic resin for 2Lsample solutions with ammonium and nitrate concentration of0.5,1.0,5.0mg/L is95.1%,elution recovery is95%,showing insignificant isotope fractionation during precipitation.Analyses of the solutions prepared from(NH4)2SO4and KNO3distributed,and also the rain,river,lake and well samples showed that the method can produce good quality of isotope measurements.

Key words:nitrogen isotope,ammonium,nitrate ion exchange resin

ReleaseDate:2016-08-31 18:47:08

[1] Conley D J,Paerl H W,Howarth,R W,et al.Controlling 671 第6期 曾海鳌,等:淡水氨氮和硝态氮氮同位素分析方法 Eutrophication:Nitrogen and Phosphorus[J].Science,2009, 323:1014-1015.

[2] Paerl H W,Xu H,McCarthy M J,et al.Controlling harmful cyanobacterial blooms in a hyper-eutrophic lake(Lake Taihu, China):The need for a dual nutrient(N&P)management strategy[J].Water Research,2011,45:1973-1983.

[3] Curt M D,Aguado P,Sánchez G,et al.Nitrogen isotope rati-os of synthetic and organic sources of nitrate water contamina-tion in Spain[J].Water,Air,and Soil Pollution,2004,151: 135-142.

[4] Li X D,Masuda H,Koba K,et al.Nitrogen isotope study on nitrate-contaminated groundwater in the Sichuan Basin,China [J].Water,Air,and Soil Pollution,2007,178:145-156.

[5] Svik A K,Mrkved P T.Use of stable nitrogen isotope frac-tionation to estimate denitrification in small constructed wet-lands treating agricultural runoff[J].Science of Total Envi-ronment,2008,392:157-165.

[6] Sakata M.A simple and rapid method forδ 15 N determination of ammonium and nitrate in water samples[J].The Geochem-ical society of Japan,2001,35(4):271-275.

[7] Silva S R,Kendall C,Wilkison D H,et al.A new method for collection of nitrate from fresh water and the analysis of nitro-gen and oxygen isotope ratios[J].Journal of Hydrology, 2000,228:22-36.

[8] Lehmann M F,Bernasconi S M,McKenzie J A.A method for the extraction of ammonium from freshwaters for nitrogen iso-tope analysis[J].Anal.Chem.,2001,73:4717-4721.

[9] Granger J,Sigman D M.Removal of nitrite with sulfamic acid for nitrate N and O isotope analysis with the denitrifier method [J].Rapid Communications in Mass Spectrometry,2009,23 (23):3753-3762.

[10] 肖化云,刘丛强.水样硝酸盐氮同位素分析预处理方法探讨 [J].岩矿测试,2002,21(2):105-108.[XIAO Huayun, LIU Congqiang.Discussion on a method for preparation ni-trate forδ 15 N analysis in water samples[J].Rock and Min-eral Analysis,2002,21(2):105-108.]

[11] Garten J R C T.Nitrogen isotope of ammonium and nitrate in bulk precipitation and forest throughfall[J].Intern J.Anal. Chem.,1992,47(1):33-45.

[12] 杨素更.地下水中硝酸盐氮同位素测定方法[J].地质实验 室,1996,12(2):96-98.[YANG Sugeng.The method of nitrateδ 15 N analysis for ground water[J].Geological Labo-ratory,1996,12(2):96-98.]

[13] Sigman D M,Casciotti K L,Andreani M,et al.A bacterial method for the nitrogen isotopic analysis of nitrate in seawa-ter and freshwater[J].Analytical Chemistry,2001,73: 4145-4153.