Document Detail

Application of hydrocyanic acid vapor generation via focused microwave radiation to the preparation of industrial effluent samples prior to free and total cyanide determinations by spectrophotometric flow injection analysis.
MedLine Citation:
PMID:  17143595     Owner:  NLM     Status:  PubMed-not-MEDLINE    
A sample preparation procedure for the quantitative determination of free and total cyanides in industrial effluents has been developed that involves hydrocyanic acid vapor generation via focused microwave radiation. Hydrocyanic acid vapor was generated from free cyanides using only 5 min of irradiation time (90 W power) and a purge time of 5 min. The HCN generated was absorbed into an accepting NaOH solution using very simple glassware apparatus that was appropriate for the microwave oven cavity. After that, the cyanide concentration was determined within 90 s using a well-known spectrophotometric flow injection analysis system. Total cyanide analysis required 15 min irradiation time (90 W power), as well as chemical conditions such as the presence of EDTA-acetate buffer solution or ascorbic acid, depending on the effluent to be analyzed (petroleum refinery or electroplating effluents, respectively). The detection limit was 0.018 mg CN l(-1) (quantification limit of 0.05 mg CN l(-1)), and the measured RSD was better than 8% for ten independent analyses of effluent samples (1.4 mg l(-1) cyanide). The accuracy of the procedure was assessed via analyte spiking (with free and complex cyanides) and by performing an independent sample analysis based on the standard methodology recommended by the APHA for comparison. The sample preparation procedure takes only 10 min for free and 20 min for total cyanide, making this procedure much faster than traditional methodologies (conventional heating and distillation), which are time-consuming (they require at least 1 h). Samples from oil (sour and stripping tower bottom waters) and electroplating effluents were analyzed successfully.
Maria Cristina Baptista Quaresma; Maria de Fátima Batista de Carvalho; Francis Assis Meirelles; Vânia Maria Junqueira Santiago; Ricardo Erthal Santelli
Related Documents :
15881605 - Spectrofluorometric determination of some beta-blockers in tablets and human plasma usi...
18964295 - Determination of ultratrace amounts of cobalt by catalysis of the tiron-hydrogen peroxi...
18967535 - Simple and specific method for flow injection analysis determination of cationic surfac...
11601455 - Determination of salicylate in blood serum by flow injection with immobilized salicylat...
8143675 - The determination of cocaine and related substances by micellar electrokinetic capillar...
977705 - Analysis of benzoylecgonine in urine by high-performance liquid chromatography and gas ...
Publication Detail:
Type:  Journal Article     Date:  2006-12-02
Journal Detail:
Title:  Analytical and bioanalytical chemistry     Volume:  387     ISSN:  1618-2642     ISO Abbreviation:  Anal Bioanal Chem     Publication Date:  2007 Feb 
Date Detail:
Created Date:  2007-01-29     Completed Date:  2007-05-15     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  101134327     Medline TA:  Anal Bioanal Chem     Country:  Germany    
Other Details:
Languages:  eng     Pagination:  1017-25     Citation Subset:  -    
Departamento de Geoquímica, Universidade Federal Fluminense, Outeiro de São João Batista s/n, Centro, 24020-150, Niterói, RJ, Brazil.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  The affective experience of the analyst in the extra-analytic moment.
Next Document:  Fourier transform infrared imaging and MR microscopy studies detect compositional and structural cha...