A flow sampling strategy for the analysis of oil samples without pre-treatment in a sequential injection analysis system

• Type: Article in International Scientific Journal
• Date: 2006

Authors

Pinto, PCAG (Author) FFUP; Lucia, M (Author) Other; Saraiva, MF (Author) FFUP; Lima, JLFC (Author) FFUP

Journal

Title: Analytica Chimica Acta

Vol. 555 No. 2

Pages: 377-383

ISSN: 0003-2670

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 17 Citations

ISI Web of Science

Scopus - 19 Citations

Scientific classification

CORDIS: Health sciences

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-004-NPP

DOI: 10.1016/j.aca.2005.09.009

Resumo (PT): The present work describes a sequential injection analysis (SIA) system adapted to direct analysis of oil samples. In this way, the flow system was designed by incorporation, in the SIA system, of an injection valve that was responsible for the sample insertion. With the developed sampling strategy the sample pre-treatment outside the flow system is avoided and also the problems associated with viscous samples in flow systems. The developed SIA system was applied to the determination of iron (Fe(III)) in edible oil samples and was based on the formation of a red complex (λ = 510 nm) between Fe(III) and thiocyanate in organic medium. A mixture of methanol:chloroform (85:15) was used as carrier solution and possible refractive index associated with the spectrophotometric detection was avoided by introduction of a mixing chamber in the flow system. The presented methodology produced 4.2 ml of effluent and consumed 150 μl of sample and 0.95 mg of thiocyanate per determination. Linear calibration plots were obtained for Fe(III) concentrations up to 25 mg l−1 and the detection limit of the determination was 0.31 mg l−1. The developed methodology exhibited a good precision, with an R.S.D. < 3.5% (n = 15) and a determination frequency of 20 determinations h−1. The results of the analysis were evaluated by recovery studies (96.5–104.5%) and by the analysis of two AOCS reference samples. <br> <br> Keywords: Sequential injection analysis; Edible oil; Sampling strategy; Organic medium; Iron <br> <a href="http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TF4-4H98T63-3&_user=2460038&_coverDate=01%2F12%2F2006&_rdoc=30&_fmt=high&_orig=browse&_srch=doc-info(%23toc%235216%232006%23994449997%23614160%23FLA%23display%23Volume)&_cdi=5216&_sort=d&_docanchor=&_ct=34&_acct=C000057398&_version=1&_urlVersion=0&_userid=2460038&md5=fc0843177e1fdd5e0358ea85d36a8cbd">Texto integral</a> <br> <br>

Abstract (EN): The present work describes a sequential injection analysis (SIA) system adapted to direct analysis of oil samples. In this way, the flow system was designed by incorporation, in the SIA system, of an injection valve that was responsible for the sample insertion. With the developed sampling strategy the sample pre-treatment outside the flow system is avoided and also the problems associated with viscous samples in flow systems. The developed SIA system was applied to the determination of iron (Fe(III)) in edible oil samples and was based on the formation of a red complex (lambda =510 nm) between Fe(HI) and thiocyanate in organic medium. A mixture of methanol: chloroform (85:15) was used as carrier solution and possible refractive index associated with the spectrophotometric detection was avoided by introduction of a mixing chamber in the flow system. The presented methodology produced 4.2 ml of effluent and consumed 150 mu l of sample and 0.95 mg of thiocyanate per determination. Linear calibration plots were obtained for Fe(III) concentrations up to 25 mg l(-1) and the detection limit of the determination was 0.31 mg The developed methodology exhibited a good precision, with an R.S.D. < 3.5% (n = 15) and a determination frequency of 20 determinations h(-1). The results of the analysis were evaluated by recovery studies (96.5-104.5%) and by the analysis of two AM reference samples.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7