RAPID, SMALL-VOLUME, FLOW-INJECTION ANALYSIS FOR SIGMA-CO2 AND NH4+ IN MARINE AND FRESH-WATERS

被引:453
作者
HALL, PO
ALLER, RC
机构
[1] CHALMERS UNIV TECHNOL,S-41296 GOTHENBURG,SWEDEN
[2] SUNY STONY BROOK,MARINE SCI RES CTR,STONY BROOK,NY 11794
关键词
D O I
10.4319/lo.1992.37.5.1113
中图分类号
Q [生物科学];
学科分类号
07 ; 0710 ; 09 ;
摘要
SIGMACO2 and NH4+ in natural waters can be rapidly (approximately 60 samples h-1),precisely (approximately 1% RSD), and simply determined in small samples (20 mul, SIGMACO2; 50 mul, NH4+) with an inexpensive flow injection analysis system (FIA). A gas-permeable membrane is used to remove CO2 or NH3 from acidic (SIGMACO2) or basic (NH4+) reagent streams into a receiving stream and conductivity detector. Linear negative responses occur over a wide range of concentrations (<0.1-20 mM SIGMACO2; 0.1-100 muM NH4+). Adding Zn2+ to sulfidic samples prevents H2S interferences for CO2 and allows determination of H2S at high concentration (>0.1 mM) by difference (with, without Zn). Interferences from fatty acids (SIGMACO2) and methylamines (NH4+) are unlikely at natural levels. These methods correlate well with traditional techniques.
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页码:1113 / 1119
页数:7
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