Sequential injection analysis of nitrites and nitrates in human serum using nitrate reductase

• Type: Article in International Scientific Journal
• Date: 2003

Authors

Pinto, PCAG (Author) Other; Lima, JLFC (Author) FFUP; Saraiva, MLMFD (Author) FFUP

Journal

Title: Clinica Chimica Acta

Vol. 337 No. 1

Pages: 69-76

ISSN: 0009-8981

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 23 Citations

ISI Web of Science

Scopus - 23 Citations

Scientific classification

CORDIS: Health sciences

FOS: Engineering and technology > Medical engineering

Other information

Authenticus ID: P-000-EHZ

DOI: 10.1016/j.cccn.2003.07.012

Resumo (PT): Nitrates and nitrites, as products of nitric oxide in human serum, are currently used as markers in many diseases. A sequential injection analysis (SIA) flow system, for their determination in serum, is presented. The exact timing of fluidic manipulations and the small volumes used in the automated SIA systems provide exquisite control of the reaction conditions and an economy in the biological fluid and enzymes used. Methods: For nitrite determinations, 150 μl of sample and 50 μl of Griess reagent were sequentially aspirated to the system and sent to the detector. Nitrates were determined as nitrites after reduction through 0.09 U of nitrate reductase and 75 μl of NADPH. Results: Nitrates and nitrites were determined at concentrations up to 4 and 3 mg/l, respectively, with relative standard deviation (rsd) <5%. Detection limits of 0.14 and 0.03 mg/l, respectively, were calculated. Statistical evaluation showed good agreement between the results obtained, for 15 deproteinized serum samples, with both the SIA system and the comparison batch procedure. Conclusions: The automatic developed method seems to be a good alternative for routine implementation since it is four times faster, and it requires one third of sample and one half of nitrate reductase than the comparison batch procedure. <br> <br> Keywords: Human serum; Sequential injection analysis; Nitrate; Nitrite; Nitrate reductase <br> <a target="_blank" href="http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T57-49JPSSS-5&_user=2460038&_coverDate=11%2F30%2F2003&_rdoc=9&_fmt=high&_orig=browse&_srch=doc-info(%23toc%234995%232003%23996629998%23464317%23FLA%23display%23Volume)&_cdi=4995&_sort=d&_docanchor=&_ct=30&_acct=C000057398&_version=1&_urlVersion=0&_userid=2460038&md5=c7cbb9ecd43cf47e0da0a1b423ad4bb1"> Texto integral</a> <br> <br>

Abstract (EN): Background: Nitrates and nitrites, as products of nitric oxide in human serum, are currently used as markers in many diseases. A sequential injection analysis (SIA) flow system, for their determination in serum, is presented. The exact timing of fluidic manipulations and the small volumes used in the automated SIA systems provide exquisite control of the reaction conditions and an economy in the biological fluid and enzymes used. Methods: For nitrite determinations, 150 mul of sample and 50 mul of Griess reagent were sequentially aspirated to the system and sent to the detector. Nitrates were determined as nitrites after reduction through 0.09 U of nitrate reductase and 75 mul of NADPH. Results: Nitrates and nitrites were determined at concentrations up to 4 and 3 mg/l, respectively, with relative standard deviation (rsd) < 5%. Detection limits of 0.14 and 0.03 mg/l, respectively, were calculated. Statistical evaluation showed good agreement between the results obtained, for 15 deproteinized serum samples, with both the SIA system and the comparison batch procedure. Conclusions: The automatic developed method seems to be a good alternative for routine implementation since it is four times faster, and it requires one third of sample and one half of nitrate reductase than the comparison batch procedure.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8