Fast extraction of polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran in sewage sludge and soil samples

Abstract

The current environmental legislations recommend monitoring chemical contaminants such as polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans before the use of sewage sludge on the agricultural land. In this study, a solid-liquid extraction with low-temperature purification (SLE-LTP) was optimized and validated to determine 2,3,7,8-tetrachlorodibenzo-p-dioxin and 2,3,7,8-tetrachlorodibenzofuran in sewage sludge and soil samples. The analyses were performed by gas chromatography-mass spectrometry operating in the selective ion mode (GC-MS-SIM). Acetonitrile:ethyl acetate 6.5:1.5 (v/v) was the best extraction phase, and the recoveries percentages were close to 100%. The linearity was demonstrated in the range of 1.25-25 µg L of 1.25-20 µg L for sewage sludge and soil, respectively. Matrix effect was proved for the two compounds and in the two matrices studied. Extraction percentages were between 78 and 109% and relative standard deviations ≤ 19%. The proposed method is faster than methods described in the literature because showed a few steps. The quantification limits (LOQ) in sewage sludge were 6.4 and 32 ng TEQ kg for 2,3,7,8-TCDF and 2,3,7,8-TCDD, respectively. In soil, LOQs were 0.8 and 8.0 ng TEQ kg for 2,3,7,8-TCDF and 2,3,7,8-TCDD, respectively. These values are lower than the maximum residue limits established by European Legislation. The method was applied to 22 agricultural soil samples from different Brazilian cities and 2,3,7,8-TCDF was detected in one of these samples.

Simultaneous Determination of 2,3,7,8-TCDD and 2,3,7,8-TCDF in Water Samples by LLE-LTP and HPLC-DAD

“…Therefore, acetonitrile was chosen as the appropriate phase for extracting these compounds in water. Similar results were reported by Andrade et al 20 and Silvério et al 22 using the same extraction phase.…”

“…23,24 The presence of PCDD/Fs in real samples depends on several factors such as matrix type, analyte concentration, sample collection period and extraction and detection methodologies used; therefore, most of the literature studies did not quantify PCDD/Fs in real samples. 1,17,18,20,25,26…”

“…19 Recently, solid-liquid extraction with low-temperature purification (SLE-LTP) was reported as an easy, fast and efficient methodology for extracting PCDD/Fs from agricultural soil and sewage sludge. 20 Despite the success of SLE-LTP in the extraction of PCDD/Fs from solid matrices, there are no reports on this methodology for analyzing these compounds in water. In aqueous samples, this methodology is called liquidliquid extraction with low-temperature partition (LLE-LTP).…”

“…22 After extractions, these compounds are analyzed by different techniques such as high resolution gas chromatography coupled to high resolution mass spectrometry (HRGC-HRMS), which has been applied as a reference methodology established by the USEPA. 19 However, other alternative methodologies have been used such as gas chromatography coupled to mass spectrometry (GC-MS), 20 gas chromatography coupled to electron capture detection (GC-ECD), 1 gas chromatography coupled to mass spectrometry with triple quadrupole detector (GC-MS/MS), 8 high-performance liquid chromatography coupled to ultraviolet detection (HPLC-UV) 18,[23][24][25][26] and high-performance liquid chromatography coupled to fluorescence detection (HPLC-FD). 17,27 This paper aimed to optimize and validate the liquidliquid extraction with low-temperature partition and analyses by high-performance liquid chromatography coupled a diode array detector method (LLE/LTP-HPLC/DAD) for the determination of 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) and 2,3,7,8-tetrachlorodibenzofuran (2,3,7,8-TCDF) in water samples.…”

Extraction Method for Determining Florpyrauxifen-benzyl Herbicide in Soil

“…In this sense, previous works have shown that solid-liquid extraction coupled with low-temperature purification (SLE-LTP) has met these characteristics when applied to other environmental contaminants. 15,16 One of the main advantages of this methodology is the extraction and cleaning in a single step.…”