title: Determination of low level nitrite and nitrate in biological, food and environmental samples by gas chromatography-mass spectrometry and liquid chromatography with fluorescence detection.
abstract: Gas chromatography-mass spectrometry (GC-MS) and liquid chromatography with fluorescence detection (LC-FL) methods have been proposed for the determination of low level nitrite and nitrate in biological, food and environmental samples. The methods include derivatization of aqueous nitrite with 2,3-diaminonaphthalene (DAN), enzymatic reduction of nitrate to nitrite, extraction with toluene and chromatographic analyses of highly fluorescent 2,3-naphthotriazole (NAT) derivative of nitrite by using GC-MS in selected-ion-monitoring (SIM) mode and LC-FL. Nitrite and nitrate ions in solid samples were extracted with 0.5M aqueous NaOH by sonication. The recoveries of nitrite and nitrate ions based on GC-MS and LC-FL results were 98.40% and 98.10% and the precision of these methods, as indicated by the relative standard deviations (RSDs) were 1.00% for nitrite and 1.20% for nitrate, respectively. The limits of detection of the GC-MS in SIM mode and LC-FL methods based on S/N=3 were 0.02 and 0.29 pg/ml for nitrite and 0.03 and 0.30 pg/ml for nitrate, respectively.
authors: Zonguldak Karaelmas University, Faculty of Arts and Sciences, Department of Chemistry, 67100 Zonguldak, Turkey. makyuz2004@yahoo.co.uk
authors: Mehmet
authors: M
authors: Akyüz
authors: Sevket
authors: S
authors: Ata
mesh_terms: D015081:2-Naphthylamine / Q000031:analogs & derivatives / Q000737:chemistry; D002849:Chromatography, Gas; D002853:Chromatography, Liquid; D004777:Environment; D005504:Food Analysis / Q000379:methods*; D005750:Gastric Juice / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D013058:Mass Spectrometry; D009249:NADP / Q000737:chemistry / Q000378:metabolism; D050901:Nitrate Reductase / Q000737:chemistry / Q000378:metabolism; D009566:Nitrates / Q000032:analysis* / Q000097:blood / Q000737:chemistry / Q000652:urine; D009573:Nitrites / Q000032:analysis* / Q000097:blood / Q000737:chemistry / Q000652:urine; D015203:Reproducibility of Results; D012972:Sodium Hydroxide / Q000737:chemistry; D013010:Sonication; D013050:Spectrometry, Fluorescence; D014230:Triazoles / Q000737:chemistry; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000097:blood / Q000737:chemistry / Q000652:urine
chemical_list: D009566:Nitrates; D009573:Nitrites; D014230:Triazoles; D014874:Water Pollutants, Chemical; D014867:Water; C056926:1H-naphtho(2,3-d)triazole; C026373:2,3-diaminonaphthalene; D009249:NADP; D012972:Sodium Hydroxide; D015081:2-Naphthylamine; D050901:Nitrate Reductase