Simultaneous determination of preservatives in soft drinks, yogurts and sauces by a novel solid-phase extraction element and thermal desorption-gas ... [An article from: Analytica Chimica Acta]
Book Details
Author(s)L. Wang, X. Zhang, Y. Wang, W. Wang
PublisherElsevier
ISBN / ASINB000P6OU0K
ISBN-13978B000P6OU06
AvailabilityAvailable for download now
Sales Rank99,999,999
MarketplaceUnited States 🇺🇸
Description
This digital document is a journal article from Analytica Chimica Acta, published by Elsevier in 2006. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.
Description:
A novel solid-phase extraction element combined with thermal desorption-gas chromatography (TD-GC) using a pyrolysis-GC system was applied for the determination of the five preservatives - benzoic acid, sorbic acid, and methyl, ethyl and propyl esters of p-hydroxybenzoic acid - in soft drinks, yogurts and sauces. The extraction element is made of a titanium (Ti) tubing (30mmx1.2mm i.d.x1.6mm o.d.) coated with a chemically bonded layer of polydimethylsiloxane (PDMS) to a thickness of 500@mm. A sample pH of 2.0, sample volume of 5ml, extraction time of 45min with addition of salt (15% m/v NaCl) and TD temperature from 40 to 280^oC at a heating rate of 40^oCmin^-^1 and maintained at 280^oC for 9min, were selected as optimum extraction and desorption conditions. The linearity of the method was satisfactory over a concentration range of 2-1000mgL^-^1 for benzoic acid and sorbic acid, 0.2-300mgL^-^1 for methyl ester of p-hydroxybenzoic acid, and 0.02-300mgL^-^1 for ethyl and propyl esters of p-hydroxybenzoic acid, and the correlation coefficients were higher than 0.997. The limit of detection ranged from 0.002 to 0.2mgL^-^1. The potential of the proposed method was assessed by applying it to the determination of preservatives in real samples. The recoveries (92-106%) and precisions (R.S.D.s of 0.9-4.6% (n=5)) of the method were examined by analyzing soft drink, yogurt and sauce samples spiked at levels of between 20 and 100mgL^-^1. This simple, accurate and highly sensitive method may be used in the determination of the preservatives in various water-based food samples.
Description:
A novel solid-phase extraction element combined with thermal desorption-gas chromatography (TD-GC) using a pyrolysis-GC system was applied for the determination of the five preservatives - benzoic acid, sorbic acid, and methyl, ethyl and propyl esters of p-hydroxybenzoic acid - in soft drinks, yogurts and sauces. The extraction element is made of a titanium (Ti) tubing (30mmx1.2mm i.d.x1.6mm o.d.) coated with a chemically bonded layer of polydimethylsiloxane (PDMS) to a thickness of 500@mm. A sample pH of 2.0, sample volume of 5ml, extraction time of 45min with addition of salt (15% m/v NaCl) and TD temperature from 40 to 280^oC at a heating rate of 40^oCmin^-^1 and maintained at 280^oC for 9min, were selected as optimum extraction and desorption conditions. The linearity of the method was satisfactory over a concentration range of 2-1000mgL^-^1 for benzoic acid and sorbic acid, 0.2-300mgL^-^1 for methyl ester of p-hydroxybenzoic acid, and 0.02-300mgL^-^1 for ethyl and propyl esters of p-hydroxybenzoic acid, and the correlation coefficients were higher than 0.997. The limit of detection ranged from 0.002 to 0.2mgL^-^1. The potential of the proposed method was assessed by applying it to the determination of preservatives in real samples. The recoveries (92-106%) and precisions (R.S.D.s of 0.9-4.6% (n=5)) of the method were examined by analyzing soft drink, yogurt and sauce samples spiked at levels of between 20 and 100mgL^-^1. This simple, accurate and highly sensitive method may be used in the determination of the preservatives in various water-based food samples.
