SPME determination of low concentration levels of monoaromatic chemical markers in soils after remediation by supercritical fluid extraction

Abstract

Soil contamination by organic compounds has been a serious concern over the years. Among the various forms of pollutant release, gas station contamination has been widely emphasized. The presence of simple aromatic compounds in soils sampled near gas stations may indicate contamination, considering that such compounds are frequently found in petroleum-derived products. The present paper reports on the development of a process that uses pressurized fluids for the remediation of contaminated soils.Supercritical fluid extraction (SFE) employing CO 2 as the solvent and an 11.0 g capacity extraction cell was utilized. In order to demonstrate the efficiency of the process, an analytical procedure employing headspace-solid phase micro extraction (HS-SPME) as the sample preparation method and GC-MS as the separation technique was optimized and validated. Limits of quantification and detection obtained were in agreement with the values established by national and international regulatory agencies. The linear range obtained was from 10 to 260 mg kg À1 , with determination coefficients r 2 > 0.98 for all analyses. Different removal rates were observed for the contaminants studied, the best results being achieved by employing CO 2 in a supercritical state.

Gas chromatography–mass spectrometry analysis of organic pollutants in French soils irrigated with agro-industrial wastewater

“…In the case of phenolic compounds, the LOQ were significantly higher, around 50 ng•g −1 . The LOQ values obtained in this paper for the analysis of BTEX and PAH in soils are similar to those reported in previous studies also measured by GC-MS but after solid-phase microextraction (SPME) extraction for BTEX (Franco et al, 2015) or solvent extraction for PAH (Maliszewska-Kordybach et al, 2009). A significant decrease of the detection limits could be reached for alkylphenols by including a derivation step with N-methyltrifluoroacetamide (Zhang et al, 2009) and an alkylation step for tributyltin (Crnoja et al, 2001).…”

Determination of phenolic acids in Prunella vulgaris L.: a safe and green extraction method using alcohol-based deep eutectic solvents

“…Rosmarinic acid and salviaaside were isolated from the whole plant of Prunella vulgaris and their structures were elucidated by different spectroscopic methods including 1 H nuclear magnetic resonance spectrometry ( 1 H-NMR), 13 C nuclear magnetic resonance spectroscopy ( 13 C-NMR), and mass spectrometry (MS), and were conrmed by comparing the data with those of previous studies. The compound purity was over…”

“…Until now, the number of available green solvents for extracting natural products has been rather limited. In this sense, some of these new "Green Solvents" including water, 12 supercritical uids 13 and ionic liquids (ILs) 14,15 have received growing interest over the last two decades. 16 Water and supercritical uids like scCO 2 are benecial because they are nontoxic, relatively inert, and easily removable when applied to extracting natural products.…”

Development of on-line molecularly imprinted solid phase extraction-liquid chromatography-mass spectrometry for triazine analysis in corn samples

“…Triazine herbicides have been applied to the pre-and post-emergence control of weed for agricultural and non-agricultural purposes. 1,2 The intensive use of herbicides in large agricultural areas has raised concerns about their effects on the environment, as triazines and their degradation products are very toxic and stable for many years. 3 The Environmental Protection Agency (EPA) requires the tolerance of triazine herbicides up to 0.25 mg kg À1 and the Brazilian Health Surveillance Agency (ANVISA) dictates that the concentration of atrazine and simazine must not exceed 0.02 and 0.25 mg kg À1 , respectively, in corn crops.…”