A highly sensitive and selective spectrofluorimetric method for the determination of molybdenum at pico-trace levels in various matrices using N-(pyridin-2-yl)-quinoline-2-carbothioamide
Open Access
- 31 March 2021
- journal article
- Published by European Journal of Chemistry in European Journal of Chemistry
- Vol. 12 (1), 1-12
- https://doi.org/10.5155/eurjchem.12.1.1-12.2031
Abstract
A new spectrofluorimetric reagent N-(pyridin-2-yl)-quinoline-2-carbothioamide (PQTA) has been synthesized and characterized. A very simple, ultra-sensitive, and highly selective, and non-extractive new spectrofluorimetric method for the determination of molybdenum at pico-trace levels using PQTA has been developed. This novel fluorimetric reagent PQTA, becomes oxidized in a slightly acidic (0.0025-0.05 M H2SO4) solution with molybdenum (VI) in absolute ethanol to produce a highly fluorescent oxidized product (λex = 300 nm; λem= 377 nm). Constant and maximum fluorescence intensities were observed over a wide range of acidity (0.0025-0.0500 M H2SO4) for the period between 2 min and 24 h. Linear calibration graphs were obtained for 0.001-600 μg/L of Mo having a detection limit of 0.15 ng/L; the quantification limit of the reaction system was found to be 1.5 ng/L and the RSD was 0-2%. A large excess of over 60 cations, anions, and complexing agents like chloride, phosphate, azide, tartrate, oxalate, and SCN- etc. do not interfere in the determination. The developed method was successfully used in the determination of molybdenum in several Certified Reference Materials (Alloys, steel, serum, bovine liver, drinking water, soil, and sediments) as well as in some environmental waters (Potable and polluted), biological fluids (Human blood, urine, hair, and milk), soil samples and food samples (Vegetables, rice, and wheat) solutions containing both molybdenum (VI) and molybdenum (V) ions. The results of the proposed method for assessing biological, food and vegetable samples were comparable with ICP-OES and AAS were found to be in excellent agreement.Keywords
This publication has 44 references indexed in Scilit:
- Determination of molybdenum in biological samples by flame atomic spectrometry after preconcentration on activated carbonMonatshefte für Chemie / Chemical Monthly, 2011
- Determination of molybdenum in environmental samplesAnalytica Chimica Acta, 2007
- Spectrofluorimetric determination of trace amounts of molybdenum in pig liver and musselsAnalytica Chimica Acta, 2001
- Determination of Trace Amounts of Molybdenum in Waters with Carminic Acid by Ion-Exchange SpectrofluorimetryAnalytical Letters, 1994
- Simultaneous spectrofluorimetric determination of traces of molybdenum and boron in plant leavesAnalytica Chimica Acta, 1993
- Simultaneous determination of molybdenum and tungsten by first-derivative synchronous solid-phase spectrofluorimetryAnalytica Chimica Acta, 1992
- 2-(α-pyridyl)thioquinaldinamide: a novel fluorimetric reagent in inorganic trace analysis. : Part 2. A simple selective determination of selenium(IV) at Ultratrace LevelsAnalytica Chimica Acta, 1988
- Triazene-N-oxides as new type of fluorimetric reagents. part i. trace determination of zirconium at the nanogram levelMicrochimica Acta, 1984
- The role of molybdenum in human biologyJournal of Inherited Metabolic Disease, 1983
- The Willgerodt Reaction Applied to α- and γ-AlkylpyridinesJournal of the American Chemical Society, 1954