Analysis of salicylate and benzophenone-type UV filters in soils and sediments by simultaneous extraction cleanup and gas chromatography-mass spectrometry.

An analytical method for the determination of UV filters in soil and sediment has been developed and validated considering benzophenones (BP) and salicylates as target analytes. Soil and sediment samples were extracted with ethyl acetate-methanol (90:10, v/v) assisted with sonication, performing a simultaneous clean-up step. Quantification of these compounds was carried out by gas chromatography-mass spectrometry (GC-MS) after derivatization of the extracts with N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA). Recoveries from spiked soil samples ranged from 89.8% to 104.4% and they were between 88.4% and 105.3% for spiked sediment samples. The effect of the residence time and soil moisture content on the recovery of these compounds was also studied. The precision, expressed as relative standard deviation, was in all cases below 6.1% and the limits of detection (S/N=3) varied from 0.07 to 0.10 ng g(-1) and from 0.11 to 0.28 ng g(-1) for soils and sediments, respectively. The validated method was applied to the analysis of five benzophenone and two salicylate UV filters in soil and sediment samples collected in different areas of Spain.

Determination of cyclic and linear siloxanes in soil samples by ultrasonic-assisted extraction and gas chromatography-mass spectrometry.

A rapid method, based on sonication-assisted extraction in small columns (SAESC) and subsequent quantification and identification by gas chromatography-mass spectrometry (GC-MS), was developed for the determination of cyclic and linear siloxanes in soil. In the experiments with spiked samples (10-50 ng g(-1)), the recovery of cyclic and linear siloxanes ranged from 87.7 to 108.0% and from 84.9 to 107.6%, respectively. The validated method was used to determine the levels of these compounds in various types of soil samples collected from different locations in Spain. The cyclic siloxanes, decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6) were detected in all the soil samples analyzed at concentrations from 9.2 to 56.9 ng g(-1) for D5 and from 5.8 to 27.1 ng g(-1) for D6 in agricultural soils and from 22 to 184 ng g(-1) for D5 and from 28 to 483 ng g(-1) for D6 in industrial soils. The total linear siloxanes concentrations (L5-L14) (sum of the 10 congeners) ranged from 191 to 292 ng g(-1) in agricultural soils and from 1411 to 8532 ng g(-1) in industrial soils.

Determination of triclosan and methyl triclosan in environmental solid samples by matrix solid-phase dispersion and gas chromatography-mass spectrometry.

In this study, a method for the determination of triclosan (TCS) and methyl triclosan (MTCS) in soil and sewage sludge samples from municipal wastewater treatment plants was developed based on the extraction by matrix solid-phase dispersion. After extraction, the analytes were derivatized with N-(tert-butyldimethylsilyl)-N-methyl-trifluoroacetamide for their determination by isotope dilution GC with electron impact MS detection in the SIM mode, using (13)C(12)-labeled compounds as internal standards. Recoveries of MTCS and TCS from laboratory spiked sludge samples were in the range from 95.7 to 101.0% and 97.4 to 101.3%, respectively. In the case of soil samples, the recoveries of MTCS and TCS ranged from 98.4 to 101.0% and 98.7 to 99.0%, respectively. The limits of detection (S/N=3) varied from 0.10 to 0.12 ng/g for sewage sludge samples and from 0.05 to 0.08 ng/g for soil samples. The validated method was used to assess the levels of TCS and MTCS in sewage sludge collected from 19 wastewater treatment plants located in Madrid (Spain) and in soil samples collected from agricultural fields in Madrid. Both compounds were detected in all the sludge samples at concentrations ranging from 54 to 2987 ng/g dry weight for TCS and from 4 to 311 ng/g dry weight for MTCS. The levels encountered in soil were much lower, 0.8 to 4.7 ng/g dry weight for TCS and 0.3 to 3.8 ng/g dry weight for MTCS.

Determination of tetrabromobisphenol-A, tetrachlorobisphenol-A and bisphenol-A in soil by ultrasonic assisted extraction and gas chromatography-mass spectrometry.

In this work, an isotope dilution method for the determination, in agricultural and industrial soil samples, of tetrabromobisphenol-A, tetrachlorobisphenol-A and bisphenol-A by gas chromatography-mass spectrometry was developed. The compounds were extracted from soil by sonication assisted extraction in small columns (SAESC) with a low volume of ethyl acetate as extraction solvent. For dirty soil samples, such as industrial soils, a simultaneous clean-up on an acidified Florisil-anhydrous sodium sulfate mixture was carried out to remove interferences. After extraction, solvent was evaporated and analytes were derivatized with N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) and determined by isotope dilution gas chromatography with electron impact mass spectrometric detection in the selected ion monitoring mode (GC-MS-SIM), using (13)C(12) labeled compounds as internal standards. Recoveries from spiked samples were between 88% and 108% and the estimated limits of detection (S/N=3) varied from 30 pg g(-1) to 90 pg g(-1). The response obtained with this method was linear over the range assayed, 5-300 ng ml(-1), with correlation coefficients equal or higher than 0.999. The validated method was used to investigate the levels of these phenolic compounds in soil samples collected from different locations in Spain. Bisphenol-A was detected in all samples at concentrations from 0.7 ng g(-1) to 4.6 ng g(-1) in agricultural soils and from 1.1 ng g(-1) to 44.5 ng g(-1) in industrial soils. Tetrabromobisphenol-A was found in various soil samples at levels in the range of 3.4-32.2 ng g(-1) in industrial soils and at 0.3 ng g(-1) in one agricultural soil, whereas tetrachlorobisphenol-A was not detected.

Determination of polybrominated diphenyl ethers in human hair by gas chromatography-mass spectrometry.

A rapid analytical method has been developed for the determination of polybrominated diphenyl ethers (PBDEs) in human hair. PBDEs were determined by gas chromatography with electron ionization mass spectrometric detection in the selected ion monitoring mode (GC-MS-SIM). A 200mg amount of hair samples was overnight digested in 3N HCl and then PBDEs extracted with n-hexane. After clean up of extracts in a Florisil column, PBDEs were analyzed by GC-MS. The method has been validated by spiking human hair at five concentration levels, in the range from 5 to 25 ng/g for most compounds, and PBDEs were quantified using labelled compounds as internal standards. Recoveries of PBDEs were higher than 90%, repeatability was equal or lower than 12.5%, and reproducibility lower than 14%, expressed as relative standard deviation (RSD). Limits of detection (LOD) were in the range 0.08-0.9 ng/g and limits of quantification (LOQ) were between 0.27 and 3.0 ng/g. This method was applied to the determination of PBDEs in hair samples from 16 individuals and 5 PBDE congeners were detected in most of the samples. BDE-209 was the dominant compound found, followed by BDE-47, BDE-99, BDE-100, and BDE-190. BDE-209 was found in 12 out of 16 hair samples, and the total levels of PBDEs ranged from 1.4 to 19.9 ng/g.

Analysis of polybrominated diphenyl ethers in sewage sludge by matrix solid-phase dispersion and isotope dilution GC-MS.

A method for the determination of 14 polybrominated diphenyl ethers (PBDEs) in sludge from wastewater treatment plants is presented. PBDEs were extracted by matrix solid-phase dispersion assisted by sonication and determined by isotope dilution gas chromatography with electron impact mass spectrometric detection in the selected ion monitoring mode, using labelled( 13)C-PBDEs as internal standards. The limits of detection and quantification for the tri- to hepta-BDEs were in the range of 0.05 to 0.5 ng/g dry weight and 0.15 to 1.8 ng/g dry weight, respectively, and 1.6 ng/g dry weight and 5.6 ng/g dry weight for deca-BDE-209. The proposed analytical method was applied to determine PBDE levels in sewage sludge samples collected from 19 water treatment plants located in the province of Madrid (Spain). In all of the examined samples, BDE-100 and BDE-154 were the main compounds found with a mean concentration of 3.9 and 2.0 ng/g, respectively. PBDEs were detected in all of the samples, and their total concentrations not considering BDE-209 were between 3.9 and 23.0 ng/g dry weight. The dominant PBDE congener in sewage sludge was BDE-209, which constituted 38.7 to 97.3% of the total, and showed concentration levels ranging from 8.1 to 717.2 ng/g dry weight.

Analysis of 27 polycyclic aromatic hydrocarbons by matrix solid-phase dispersion and isotope dilution gas chromatography-mass spectrometry in sewage sludge from the Spanish area of Madrid.

A method for the determination of 27 polycyclic aromatic hydrocarbons (PAHs) in sludge from wastewater treatment plants (WWTPs) located in urban, industrial or rural zones is presented. PAHs were extracted by matrix solid-phase dispersion (MSPD) assisted by sonication. Purification of extracts was carried out by solid-phase extraction with C(18) and PAHs were eluted with acetonitrile. PAHs were determined by isotope dilution gas chromatography with electron impact mass spectrometric detection in the selected ion-monitoring mode (GC-MS-SIM), using deuterated PAHs as internal standards. The limits of detection ranged from 0.03 ng/g for acenaphthylene to 0.45 ng/g for benzo[b]naphtho[2,1-d]thyophene. After optimization, the method was validated with a certified reference sludge. The proposed analytical method was applied to determine PAH levels in sewage sludge samples collected from 19 water treatment plants located in the province of Madrid (Spain). In most of the examined samples, phenanthrene was the main compound with a mean concentration of 1062 ng/g. PAHs were detected in all of the samples, with total concentrations between 390 and 6390 ng/g dry weight for the 27 PAHs analyzed and from 310 to 5120 ng/g dry weight for the sum of the 10 PAHs considered in the draft European Union directive.

Determination of insecticides in honey by matrix solid-phase dispersion and gas chromatography with nitrogen-phosphorus detection and mass spectrometric confirmation.

A multiresidue method was developed for the determination of 12 organophosphorus insecticides (diazinon, parathion methyl, fenitrothion, pirimiphosmethyl, malathion, fenthion, chlorpyrifos, quinalphos, methidathion, ethion, azinphosmethyl, coumaphos), one carbamate (pirimicarb), and one amidine (amitraz) in unifloral and multifloral honeys. The analytical procedure was based on the matrix solid-phase dispersion of honey on a mixture of Florisil and anhydrous sodium sulfate in small glass columns and subsequent extraction with a low volume of hexane-ethyl acetate (90 + 10, v/v), assisted by sonication. The insecticide residues were determined by capillary chromatography with nitrogen-phosphorus detection and confirmed by mass spectrometry. Average recoveries at the 0.05-0.5 microg/g levels were >80% for organophosphorus insecticides and about 60% for the other insecticides, pirimicarb and amitraz, with relative standard deviations <10%. The detection limit for the different insecticides ranged between 6 and 15 microg/kg. The main advantages of the proposed method are that extraction and cleanup are performed in a single step with a low volume of organic solvent. The method is simple, rapid, and less laborious than conventional methods. Several Spanish honeys were analyzed with the proposed method and no residues of the studied insecticides were found.