Trace Determination of Linear Alkylbenzene Sulfonates: Applicationin Artificially Polluted Soil—Carrots System

Caroline Sablayrolles,Jérôme Silvestre,Mireille Montréjaud-Vignoles,Michel Treilhou

doi:10.1155/2009/404836

Abstract

Surfactants are widely used in household and industrial products. The risk of incorporation of linear alkylbenzene sulfonates (LAS) from biosolids, wastewater, and fertilizers land application to the food chain is being assessed at present by the European Union. In the present work, a complete analytical method for LAS trace determination has been developed and successfully applied to LAS (C10–C13) uptake in carrot plants used as model. These carrots were grown in soil with the trace organics compounds added directly into the plant containers in pure substances form. LAS trace determination (μg kg−1 dry matter) in carrots samples was achieved by Soxtec apparatus and high-performance liquid chromatography-fluorescence detection. The methodology developed provides LAS determination at low detection limits (5 μg kg−1 dry matter) for carrot sample (2 g dry matter) with good recoveries rate (>90%). Transfer of LAS has been followed into the various parts of the carrot plant. LAS are generally found in the carrot leaves and percentage transfer remains very low (0.02%).

Highlights

Linear alkylbenzene sulfonates (LASs) are synthetic anionic surfactants which were introduced in the 1960s as more biodegradable replacements for highly branched alkyl benzene sulfonates [1, 2]
The present study aims at developing and optimizing a method for LASs quantitative determination to detect their potential presence in food plants Carrots (Daucus carota L.) were
Lyophilised carrots sample were spiked with LASs mixture (500 μg kg−1 dry matter) just prior to extraction to test the effectiveness of the extraction procedure

Summary

Introduction

Linear alkylbenzene sulfonates (LASs) are synthetic anionic surfactants which were introduced in the 1960s as more biodegradable replacements for highly branched alkyl benzene sulfonates [1, 2]. Available products are very complex mixtures containing homologues with alkyl chains ranging from 10 to 13 carbon units (C10–C13) It corresponds to a compromise between cleaning capacity, on the one hand and biodegrading and toxicity, on the other hand. Methods for the quantification of LASs in soil [18],in sewage sludge [18, 19], in sediment [18, 22], in biological organisms [17, 23], or in water [14, 15, 20, 24] can be reported These methods cannot be directly applied to plant analysis. Carrots are root crops with high lipid content [25] and LASs (amphiphilic nature) should be dissolved in these lipids

Experimental

Results and Discussion

C12 C11 C13

Conclusions