Decreased water: increased solids: distorted serum concentrations

Zak, Bennie; Artiss, Joseph D.

doi:10.1016/s0026-265x(02)00088-7

Cited by 2 publications

(2 citation statements)

References 19 publications

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“…The inclusion of water was taken into account in this study. Serum normally consists of 97% water . With the sample size of serum being 10 µL, approximately 9.7 µL of water was added to the reagents.…”

Section: Methodsmentioning

confidence: 99%

A novel colorimetric assay coupled with clustering algorithms and genetic algorithm partial least squares can simultaneously determine cholesterol and monounsaturated/polyunsaturated fatty acids in biological samples

Dumancas¹,

Muriuki

Purdie

et al. 2015

Euro J Lipid Sci & Tech

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Current methodologies of quantifying cholesterol and monounsaturated fatty acid (MUFA)/ polyunsaturated fatty acids (PUFAs) constitute techniques such as GC-MS and HPLC, which use expensive standards, are time consuming and require skilled labor. We sought to develop a simple, direct alternative method for the simultaneous determination of cholesterol and MUFA/PUFAs (linoleic (LA), alpha-linolenic (ALA), arachidonic (AA), eicosapentaenoic (EPA), docosahexaenoic (DHA), conjugated linoleic (CLA), and oleic (OA) acids) using a novel colorimetric test, the "Purdie Assay." The data were analyzed using a coded chemometric software which involves clustering algorithms, and genetic algorithm partial least squares (GAPLS). The colorimetric test with GAPLS simultaneously quantified these lipids without any separation of the analytes in human serum and vegetable oils and foods. We performed pattern recognition of biological and food samples using principal component analysis (PCA) and hierarchical clustering (HC). The assay successfully discriminated 11 clusters corresponding to different food and biological samples and also discriminated synthetic vegetable oil samples using PCA and HC corresponding to levels of prepared lipids. This study shows the wide range of possible applications of the assay as a novel, fast, and efficient tool for lipid quantification and classification.Practical applications: The novel assay coupled with GAPLS, PCA, and HC can provide an efficient tool for the direct determination and discrimination of unsaturated lipids in biological samples.

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Section: Methodsmentioning

confidence: 99%

A novel colorimetric assay coupled with clustering algorithms and genetic algorithm partial least squares can simultaneously determine cholesterol and monounsaturated/polyunsaturated fatty acids in biological samples

Dumancas¹,

Muriuki

Purdie

et al. 2015

Euro J Lipid Sci & Tech

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show abstract

“…It was demonstrated that water induces significant changes in the molar absorptivities of the analytes. Thus, since serum normally has a water content of approximately 97% [4]; with the sample size being 10 lL, approximately 9.7 lL of water is added to the reagents when synthetic mixtures are analyzed. In sum- mary, the procedure involves placing 10 lL of serum sample in a test tube and one milliliter of pure acetyl chloride and 40 lL PA (70%) are added sequentially, with some care, but under ambient temperature conditions.…”

Section: Brief History Of the Purdie Assay Reagent Developmentmentioning

confidence: 99%

Simultaneous spectrophotometric and chemometric determination of lipids in synthetic mixtures and human serum

Dumancas¹,

Muriuki

Purdie

et al. 2009

Lipid Technology

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This article describes the development of a new paradigm in lipid testing wherein seven major human plasma lipids are determined simultaneously without the need for analytical separations. Included are cholesterol and the esters of linoleic, conjugated linoleic (CLA), arachidonic, linolenic, eicosapentaenoic, (EPA), and docosohexaenoic acids, (DHA). The simple quantitative colorimetric assay is rapid, rugged, inexpensive and specific to the -CH=CH-CH 2 -functional group in both cyclic and acyclic structures. The critical moiety in the functional group is the a-methylene (allylic) group that triggers the reaction. Without it, a double or triple bond is not reactive. The visible spectrum for a typical plasma sample turned out to be the linear sum of the weighted contributions from all seven analytes that -given the heterogeneity of blood samples -leads to a broad diversity in the spectral patterns. To resolve the spectral data, a number of chemometric techniques were investigated. Initially, calculations were made on spectral data that originated from prepared synthetic mixtures whose molar concentrations were known. The most encouraging algorithms employed are: coupling ridge regression (RR) with K-matrix, partial least squares regression (PLS), and generalized standard addition method (GSAM). An attempt to apply GSAM to serum samples is validated using GC-MS. The same serum samples are analyzed using GC-MS and spectrophotometry and the ratios of omega-6 to omega-3 obtained from the analyses are compared. Results using both methods correspond very well. (The reaction between acetyl chloride and olefinic systems is described as a Friedel-Crafts reaction but the mechanism of this process, the structure of the products, and the nature of the resulting chromophore remains to be fully identified.)

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Decreased water: increased solids: distorted serum concentrations

Cited by 2 publications

References 19 publications

A novel colorimetric assay coupled with clustering algorithms and genetic algorithm partial least squares can simultaneously determine cholesterol and monounsaturated/polyunsaturated fatty acids in biological samples

A novel colorimetric assay coupled with clustering algorithms and genetic algorithm partial least squares can simultaneously determine cholesterol and monounsaturated/polyunsaturated fatty acids in biological samples

Simultaneous spectrophotometric and chemometric determination of lipids in synthetic mixtures and human serum

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