Simultaneous Determination of Nitrate and Nitrite in Human Plasma by Gas Chromatography-Mass Spectrometry

Abstract

We devised a sensitive and simple method for the simultaneous determination of nitrate and nitrite in human plasma, using extractive alkylation. These inorganic anions were alkylated with pentafluorobenzyl bromide, using tetradecyldimethylbenzylammonium chloride as the phase-transfer catalyst, with 1,3,5-tribromobenzene as an internal standard. The derivatives were analyzed by gas chromatography-mass spectrometry, using the negative-ion chemical ionization mode with isobutane as the reagent gas. Calibration curves for nitrate and nitrite were linear over the concentration range of 0.01 to 1.0 micromol/mL in plasma, and the lower limit of detection for both compounds was 0.005 micromol/mL. The accuracy and precision of this method were evaluated and coefficients of variation were lower than 10.4%. Blood nitrate and nitrite concentrations of six victims who committed suicide by inhaling automobile exhaust gas could be determined using our method.

Determining15N enrichment of dissolved organic nitrogen in environmental waters by gas chromatography/negative-ion chemical ionization mass spectrometry

“…DB-225 showed similar performance to HP-1701 and could be used satisfactorily, as already reported (Kage et al 2002). With HP-5MS, PFB-NO 2 and PFB-ONO 2 could not be separated sufficiently (Tsikas 2000).…”

“…We applied the developed method to measure DON production rate by the hermatypic coral Porites cylindrica during incubation with 15 N-labeled NO 3 -. E-mail: miyajima@ori.u-tokyo.ac.jp; phone: +81(0)3 5351 6525; fax: +81(0)3 5351 6461 followed by negative-ion chemical ionization gas chromatography-mass spectrometry (GC-NICI-MS) (Tsikas 2000;Kage et al 2002). For usual seawater samples, the required sample volume could be reduced to 10 mL or less, and the whole process can be completed within 9 d (in which waiting periods are 6 d without extra work).…”

Derivatization in Mass Spectrometry– 3. Alkylation (Arylation)

“…The lower limit of detection of both compounds was 0.005 mmol mL -1 . 117,118 Alkylation is one of the most widespread approaches to the analysis of chemical warfare agents by GC/MS. 119 Phosphonic acids are usually analyzed by GC/MS in the form of methyl or PFB esters The former derivatives are prepared by using diazomethane, (trimethylsilyl)diazomethane or trimethylphenylammonium hydroxide (on-line derivatization).…”

A Simple Flow Injection Spectrophotometric Determination of Nitrite Based on Its Reaction with Thiourea

“…Various methods have been used for the determination of nitrite, including chromatography, 4-7 gas chromatography-mass spectrometry, 8 capillary electrophoresis, [9][10][11] colorimetric methods, [12][13][14][15][16][17][18][19][20][21][22][23] catalytic-based methods, [24][25][26] and several other methods such as electrochemical ones, 27-29 fluorometric ones 30,31 and chemiluminescence. [32][33][34] Flow injection analysis (FIA) in combination with one of the above detection methods have been widely used for the determination of nitrite.…”