Issue 19, 2014

Development of molecularly imprinted poly(methacrylic acid)/silica for clean-up and selective extraction of cholesterol in milk prior to analysis by HPLC-UV

Abstract

In the present paper the assessment of a novel molecularly imprinted polymer, poly(methacrylic acid)/silica, for clean-up and selective extraction of cholesterol in milk samples is described. The relative selectivity coefficient (k) values for cholesterol/5-α-cholestane and cholesterol/7-dehydrocholesterol systems were found to be 5.08 and 6.08, respectively, thus attesting the selectivity of the MIP for cholesterol under competitive adsorption with structurally analogous steroid compounds. The milk analysis was initially based on saponification followed by liquid–liquid extraction with n-hexane. Then, the protocol of molecularly imprinted solid phase extraction (MISPE) was carried out by loading the milk hexanic extract through 200 mg of MIP or NIP (non-imprinted polymer) packed into SPE cartridges at a flow rate of 0.6 mL min−1. The washing step was performed by using n-hexane followed by further elution with ethanol and HPLC-UV analysis at 208 nm. From the breakthrough curve the maximum adsorption capacity of the MIP towards cholesterol was found to be 29.51 mg g−1. The precision of the MISPE protocol was assessed as intra- and inter-days yielding RSD (relative standard deviations) lower than 4.10%. Cleaner HPLC chromatograms were obtained for milk samples submitted to the MISPE protocol in comparison to the solid phase extraction using the NIP or modified octadecyl silica (C18). Recoveries varying from 96.6 up to 102.2% for milk samples spiked with cholesterol were achieved, thus ensuring the accuracy of the proposed method.

Graphical abstract: Development of molecularly imprinted poly(methacrylic acid)/silica for clean-up and selective extraction of cholesterol in milk prior to analysis by HPLC-UV

Article information

Article type
Paper
Submitted
06 abr. 2014
Accepted
19 jun. 2014
First published
19 jun. 2014

Analyst, 2014,139, 5021-5027

Author version available

Development of molecularly imprinted poly(methacrylic acid)/silica for clean-up and selective extraction of cholesterol in milk prior to analysis by HPLC-UV

D. N. Clausen, J. V. Visentainer and C. R. T. Tarley, Analyst, 2014, 139, 5021 DOI: 10.1039/C4AN00517A

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements