Romanian Journal of Ecology & Environmental Chemistry
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Analytical methods for the determination of Cr6+ from fixed source emissions


Authors: MIHAELA PETRESCU, ELENA BUCUR, VALERIU DANCIULESCU, ANDREEA COZEA, CLAUDIA MIHAELA BORCESCU, MIHAI BRATU, GHEORGHITA TANASE

Keywords: isokinetic sampling , fixed source emissions; molecular absorption spectrophotometric method (UV-VIS); the graphite furnace atomization absorption spectrometry method(GTAAS)
https://doi.org/10.21698/rjeec.2020.223

The aim of this study was to develop two analytical methods for the determination of Cr6 + from fixed source emissions, such us the molecular absorption spectrophotometric method (UV-VIS) and the graphite furnace atomization absorption spectrometry method (GTAAS). The first stage in the development of analytical methods involves establishing the optimal operating conditions for, taking air samples, treating them for analysis and the proceeding for analysis, followed by validating the method by determining performance parameters. For both methods is high recommended, the use of isokinetic sampling with a sampling probe by heated glass, quartz or PTFE. Dust from the gaseous effluent is retained on the filter. Then, the gaseous effluent is passed through a series of absorbers containing a 0.1M Na OH absorbent solution. When the gaseous effluent has a strong acid character (high concentrations of SO2, NOx. HCl, HF, etc.) is recommended to use a 0.5M NaOH absorbent solution. The maintaining of the pH at values > 8.5 in the exposed absorbent solutions was one of the conditions of validity of the sampling. The limit of detection and the limit of quantification were concluded to be 12.38 µg / m3 and 40 µg / m3, respectively for the UV-VIS method and for the GTAAS method 0.12 µg / m3 and 0.54 µg / m3 respectively.