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Titolo:
AQUEOUS NITRITE ION DETERMINATION BY SELECTIVE REDUCTION AND GAS-PHASE NITRIC-OXIDE CHEMILUMINESCENCE
Autore:
DUNHAM AJ; BARKLEY RM; SIEVERS RE;
Indirizzi:
UNIV COLORADO,DEPT CHEM & BIOCHEM,CAMPUS BOX 215 BOULDER CO 80309 UNIV COLORADO,DEPT CHEM & BIOCHEM BOULDER CO 80309 UNIV COLORADO,CIRES BOULDER CO 80309
Titolo Testata:
Analytical chemistry
fascicolo: 1, volume: 67, anno: 1995,
pagine: 220 - 224
SICI:
0003-2700(1995)67:1<220:ANIDBS>2.0.ZU;2-M
Fonte:
ISI
Lingua:
ENG
Soggetto:
CHEMI-LUMINESCENCE DETECTION; FLOW-INJECTION ANALYSIS; NITRATE; WATER;
Tipo documento:
Note
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
17
Recensione:
Indirizzi per estratti:
Citazione:
A.J. Dunham et al., "AQUEOUS NITRITE ION DETERMINATION BY SELECTIVE REDUCTION AND GAS-PHASE NITRIC-OXIDE CHEMILUMINESCENCE", Analytical chemistry, 67(1), 1995, pp. 220-224

Abstract

An improved method of now injection analysis for aqueous nitrite ion exploits the sensitivity and selectivity of the nitric oxide (NO) chemiluminescence detector, Trace analysis of nitrite ion in a small sample (5-160 mu L) is accomplished by conversion of nitrite ion to NO by aqueous iodide in acid, The resulting NO is transported to the gas phase through a semipermeable membrane and subsequently detected by monitoring the photoemission of the reaction between NO and ozone (O-3) Chemiluminescence detection is selective for measurement of NO, and, sincethe detection occurs in the gas-phase, neither sample coloration nor turbidity interfere. The detection limit for a 100-mu L sample is 0.04ppb of nitrite ion. The precision at the 10 ppb level is 2% relative standard deviation, and 60-180 samples can be analyzed per hour, Samples of human saliva and food extracts were analyzed; the results from astandard colorimetric measurement are compared with those from the new chemiluminescence method in order to further validate the latter method. A high degree of selectivity is obtained due to the three discriminating steps in the process: (1) the nitrite ion to NO conversion conditions are virtually specific for nitrite ion, (2) only volatile products of the conversion will be swept to the gas phase (avoiding turbidity or color in spectrophotometric methods), and (3) the NO chemiluminescence detector selectively detects the emission from the NO + O-3 reaction. The method is free of interferences, offers detection limits of low parts per billion of nitrite ion, and allows the analysis of up to 180 mu L-sized samples per hour, with little sample preparation andno chromatographic separation. Much smaller samples can be analyzed by this method than in previously reported batch analysis methods, which typically require 5 mt or more of sample and often need chromatographic separations as well.

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Documento generato il 05/12/20 alle ore 22:29:33