Development and validation of methods for the trace determination of phthalates in sludge and vegetables

Abstract

A routine method which is simple, quick and precise has been set up and validated for phthalate analysis in environmental samples (tomato plants and sewage sludges). Six phthalates have been studied simultaneously: dimethylphthalate, diethylphthalate, di-n-butylphthalate, n-butylbenzylphthalate, di-2-ethyl-hexyl phthalate (DEHP) and di-n-octylphthalate. Optimization of sample, solvent extraction uses a Soxtec apparatus and extract purification with an a solid-phase extraction cartridge allows between 90 and 110% recovery of phthalates. Precise, sensitive and selective identification and quantifying of analytes is by GC-MS in the single ion monitoring mode. This protocol allows analytes with concentrations as low as 10 microg/kg dry matter (DM) to be determined from small (1-2 g DM) samples. This analytical method has been applied to the phthalate transfer study for agricultural recycling of sludges, where phthalate bioavailability has been studied in aquiculture using two types of experiments. Tomatoes have been grown in containers where the trace organics have been directly introduced as pure substances, and in a second experiment under the same growth conditions, sewage sludge has replaced the pure substances. Transfer of these trace organics has been followed into the various parts of the tomato plant and in general only the DEHP is worthy of note although its percentage transfer remains very low even in an experiment designed to maximize this.

Distribution of phthalic acid esters in agricultural plants and soil

“…I). Several studies have also confi rmed the dependence of resulting concentration of DBP and DEHP in crops on the initial concentration of PAE in the soil (Yin et al, 2003;Sablayrolles et al, 2005;. When using sewage waste as a fertilizer, a signifi cant increase in the content of phthalates in soil occurs in comparison to the normal organic fertilizer (Xu and Wang, 2008;Cai et al, 2008).…”

Extraction of phthalate esters from water and beverages using a graphene-based magnetic nanocomposite prior to their determination by HPLC

“…Up to now, various pretreatment techniques have been attempted to extract PAEs from different samples, such as liquid-liquid extraction (LLE) [6,7], solid-phase extraction (SPE) [8][9][10][11][12][13], solid-phase microextraction (SPME) [14][15][16][17][18], liquid-phase microextraction (LPME) [19], LPME method based on the solidification of a floating organic microdrop (LPME-SFO) [20], accelerated solvent extraction (ASE) [21], stir-bar sorptive extraction (SBSE) [22], single-drop microextraction (SDME) [23], dispersive liquid-liquid microextraction (DLLME) [24][25][26], hollow fiber-based liquid-phase microextraction (HF-LPME) [27], polymer monolith microextraction (PMME) [28], supercritical fluid extraction [29], and ultrasound-assisted emulsification-microextraction (USAEME) [30]. Among them, SPE and SPME are the mostly used techniques for environmental analysis.…”

Validação de uma metodologia analítica para determinação de cálcio em produtos cárneos

“…No desenvolvimento e validação de métodos para determinar traços de ftalatos (ésteres de ácido ftá-lico) em vegetais, Sablayrolles et al (2005) utilizaram o método da cromatografia gasosa com espectroscopia de massa, obtendo coeficientes de correlação linear na faixa de 0,7247 a 0,9742 para baixas concentrações e 0,8840 a 0,9852 para concentrações altas. Gaberlotti, Marsiglia e Torres (2003) validaram um método enzimático gravimétrico para determinação de fibras dietéticas em alimentos, sendo o coeficiente de correlação linear igual a 0,9999 -indicativo de uma boa linearidade do método -e a curva de calibração construída com 3 níveis de concentração.…”