Optimization and Simultaneous Determination of Alkyl Phenol Ethoxylates and Brominated Flame Retardants in Water after SPE and Heptafluorobutyric Anhydride Derivatization followed by GC/MS

A gas chromatography–mass spectrometry (GC–MS) method was investigated for the simultaneous analysis of two types of endocrine disrupting compounds (EDCs), i.e., alkylphenol ethoxylates and brominated flame retardants (BFRs), by extraction and derivatization followed by GC–MS. Different solid phase extraction (SPE) cartridges (Cleanert PestiCarb, C₁₈, Cleanert-SAX and Florosil), solvents (toluene, tetrahydrofuran, acetone, acetonitrile and ethyl acetate) and bases (NaHCO₃, triethylamine and pyridine) were tested and the best chromatographic analysis was achieved by extraction with Strata-X (33?μm, Reverse Phase) cartridge and derivatization with heptafluorobutyric anhydride at 55?°C under Na₂CO₃ base in hexane. It was observed that APE together with lower substituted PBBs (PBB1, PBB10, PBB18 and PBB49), HBCD and TBBPA can be determined simultaneously under the same GC conditions. This simple and reliable analytical method was applied to determining trace amounts of these compounds from wastewater treatment plant samples. The recoveries of the target compounds from simulated water were above 60?%. The limit of detection ranged from 0.01 to 0.15?μg L^?1 and the limit of quantification ranged from 0.05 to 0.66?μg L^?1. There were no appreciable differences between filtered and unfiltered wastewater samples from Leeuwkil treatment plant although concentration of target analytes in filtered influent was slightly lower than the concentration of target analytes in unfiltered influent water. The concentrations of the target compounds from the wastewater treatment were determined from LOQ upwards.     

Determination of BTEX Compounds by Dispersive Liquid–Liquid Microextraction with GC–FID

Rapid, inexpensive, and efficient sample-preparation by dispersive liquid–liquid microextraction (DLLME) then gas chromatography with flame ionization detection (GC–FID) have been used for extraction and analysis of BTEX compounds (benzene, toluene, ethylbenzene, and xylenes) in water samples. In this extraction method, a mixture of 25.0 μL carbon disulfide (extraction solvent) and 1.00 mL acetonitrile (disperser solvent) is rapidly injected, by means of a syringe, into a 5.00-mL water sample in a conical test tube. A cloudy solution is formed by dispersion of fine droplets of carbon disulfide in the sample solution. During subsequent centrifugation (5,000 rpm for 2.0 min) the fine droplets of carbon disulfide settle at the bottom of the tube. The effect of several conditions (type and volume of disperser solvent, type of extraction solvent, extraction time, etc.) on the performance of the sample-preparation step was carefully evaluated. Under the optimum conditions the enrichment factors and extraction recoveries were high, and ranged from 122–311 to 24.5–66.7%, respectively. A good linear range (0.2–100 μg L⁻¹, i.e., three orders of magnitude; r ² = 0.9991–0.9999) and good limits of detection (0.1–0.2 μg L⁻¹) were obtained for most of the analytes. Relative standard deviations (RSD, %) for analysis of 5.0 μg L⁻¹ BTEX compounds in water were in the range 0.9–6.4% (n = 5). Relative recovery from well and wastewater at spiked levels of 5.0 μg L⁻¹ was 89–101% and 76–98%, respectively. Finally, the method was successfully used for preconcentration and analysis of BTEX compounds in different real water samples.

     

Determination of Selected Chlorinated Priority Substances in Fish using QuEChERS Method with Dual dSPE Clean-up and Gas Chromatography

A rapid and simple analytical method for the determination of ten chlorinated priority substances (hexachloro-1,3-butadiene, pentachlorobenzene, hexachlorobenzene, hexachlorocyclohexane isomers, heptachlor, and heptachlor epoxides) in fish samples using QuEChERS extraction, dual dispersive solid-phase extraction (dSPE) clean-up, and GC analysis was developed. For the extraction, two published extraction/partitioning procedures were evaluated, and the recoveries obtained for the analytes (in range 54–98 % with RSDs ≤15 %) were in favour of the conventional QuEChERS method. The use of the dual dSPE clean-up yields cleaner extracts than in the case of single dSPE, which enables the use of ECD for the detection of the analytes and simplifies the maintenance of the GC system. The method was optimised using homogenates of chub fish that is frequently sampled for monitoring purposes. The linearity of the method was evaluated using matrix-matched calibration curves (in the range 2–50 μg kg⁻¹), and correlation coefficients (r ²) in the range 0.9927–0.9992 and RSDs of the relative response factors (RRF) below the value of 20 % were achieved. LODs ranged from 0.5 to 1.1 μg kg⁻¹, while LOQs ranged from 1.5 to 3.5 μg kg⁻¹. The accuracy of the method was verified by the analysis of the NIST standard reference material SRM 1946 (Lake Superior Fish Tissue), and most of the analytes of interest presented good agreement with the certified values.

     

An automated headspace solid-phase microextraction followed by gas chromatography–mass spectrometry method to determine macrocyclic musk fragrances in wastewater samples

A fully automated method has been developed for determining eight macrocyclic musk fragrances in wastewater samples. The method is based on headspace solid-phase microextraction (HS-SPME) followed by gas chromatography–mass spectrometry (GC-MS). Five different fibres (PDMS 7 μm, PDMS 30 μm, PDMS 100 μm, PDMS/DVB 65 μm and PA 85 μm) were tested. The best conditions were achieved when a PDMS/DVB 65 μm fibre was exposed for 45 min in the headspace of 10 mL water samples at 100 °C. Method detection limits were found in the low ng L^?1 range between 0.75 and 5 ng L^?1 depending on the target analytes. Moreover, under optimized conditions, the method gave good levels of intra-day and inter-day repeatabilities in wastewater samples with relative standard deviations (n?=?5, 1,000 ng L^?1) less than 9 and 14 %, respectively. The applicability of the method was tested with influent and effluent urban wastewater samples from different wastewater treatment plants (WWTPs). The analysis of influent urban wastewater revealed the presence of most of the target macrocyclic musks with, most notably, the maximum concentration of ambrettolide being obtained in WWTP A (4.36 μg L^?1) and WWTP B (12.29 μg L^?1), respectively. The analysis of effluent urban wastewater showed a decrease in target analyte concentrations, with exaltone and ambrettolide being the most abundant compounds with concentrations varying between below method quantification limit (<MQL) and 2.46 μg L^?1.

LC–MS/MS Determination of Catecholamines in Urine Using FMOC-Cl Derivatization on Solid-Phase Extraction Cartridge

A method for the determination of catecholamine derivatives in human urine is proposed that includes the derivatization of target compounds on a solid-phase extraction cartridge and determination of the analytes by a UHPLC method with tandem mass-spectrometric detection. 9-Fluorenyl-methoxycarbonyl chloride was used as the derivatization agent. The limits of detection for the analytes were 2.5 ng mL^?1 for 9-fluorenyl-methoxycarbonyl-adrenaline, 5 ng mL^?1 for 9-fluorenyl-methoxycarbonyl-octopamine, and 25 ng mL^?1 for 9-fluorenyl-methoxycarbonyl-dopamine. The proposed procedure was tested on real samples obtained from volunteers.     

Determination of acidic pharmaceutical products and carbamazepine in roughly primary-treated wastewater by solid-phase extraction and gas chromatography–tandem mass spectrometry

A gas chromatography–tandem mass spectrometry (GC–MS/MS) method has been developed for the determination of selected pharmaceutical residues (carbamazepine, salicylic acid, clofibric acid, ibuprofen, 2-hydroxy-ibuprofen, fenoprofen, naproxen, ketoprofen, diclofenac, and triclosan) in sewage influent and roughly primary-treated effluent. The method involved solid-phase extraction (SPE) with polymeric sorbents, and two SPE cartridges were compared for the extraction and elution of the targeted compounds in complex matrices. A successful chemical derivatization of carbamazepine and acidic compounds using N,O-bis(trimethylsilyl) trifluoroacetamide +10% trimethylchlorosilane is also described. The quantification limits of the analytical procedure ranged from 30 to 60?ng?L^?1 for 500?mL of wastewater. The best recovery rates (72–102%) in spiked effluent samples were obtained with Phenomenex Strata-X? cartridges. Detection limits (S/N?=?3) were estimated at between 1 and 18?ng?L^?1. The reported GC–MS/MS method significantly reduces the strong matrix effects encountered with more expensive LC-MS/MS techniques. Application of the developed method showed that most selected analytes were detected at concentrations ranging from low µg?L^?1 to trace level ng?L^?1 in Montreal's wastewater treatment plant effluent and influent, as well as in the receiving waters at more than 8?km downstream of the effluent outfall. The rugged alternative analytical method is suitable for the simultaneous analysis of carbamazepine and pharmaceutical acidic residues in wastewater samples from influents and effluents that have undergone rough primary treatment.     

Fast Analysis of Synthetic Pyrethroid Metabolites in Water Samples Using In-Syringe Derivatization Coupled Hollow Fiber Mediated Liquid Phase Microextraction with GC-ECD

A fast and efficient method has been demonstrated for the trace determination of six important metabolites of synthetic pyrethroids including cis- and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid (cis- and trans-Cl₂CA), cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid (cis-Br₂CA), 4-fluoro-3-phenoxybenzoic acid (4-F-3-PBA), 3-phenoxybenzoic acid (3-PBA), and 2-phenoxybenzoic acid (2-PBA) in environmental water samples using hollow fiber (HF)-mediated liquid-phase microextraction (LPME) coupled with in-syringe derivatization (ISD) followed by gas chromatography (GC) with electron capture detector (ECD) analysis. This method utilizes a HF membrane segment impregnated with extraction solvent as the LPME sampling probe, which was connected to a microsyringe pre-filled with derivatizing agents, and it was immersed into sample solution for extraction. After extraction, the extracting solution was subjected to derivatization reaction that was performed inside the syringe barrel followed by GC-ECD analysis. Under optimal conditions, the best extraction efficiency was obtained using sampling probe (2.0 cm hollow fiber) impregnated with 1-octanol immersed into water sample (5.0 mL, adjusted pH below 1.0) and stirring (1,250 rpm) for 10 min at 70 °C and diisopropylcarbodiimide (2 μL) and 1,1,1,3,3,3-hexafluoro-2-propanol (1 μL) were the derivatizing agents used. The detection limits of 3 ng mL^?1 for cis- and trans-Cl₂CA, 2 ng mL^?1 for cis-Br₂CA, 6 ng mL^?1 for 4-F-3-PBA, and 0.6 ng mL^?1 for 3-PBA and 2-PBA. The method showed good linearity (R ² = 0.973?0.998), repeatability from 4.0 to 13 % (n = 5), recovery from 79.2 to 95.7 %, and enrichment factors ranged between 109 and 159 for target analytes spiked in water samples. The proposed method and conventional methods were compared. Results suggested that the proposed HF-LPME-ISD/GC-ECD method was a rapid, simple, inexpensive, and eco-friendly technique for the analysis of metabolites of pyrethroids.     

Determination of Six Resorcylic Acid Lactones in Feed by GC–MS

A method was developed to simultaneously detect six resorcylic acid lactones in feed by GC–MS. Samples were extracted with methanol followed by a two step liquid–liquid extraction and an HLB SPE clean-up. The samples were derivatized with BSTFA + TMCS (99/1; v/v) and determined by GC–MS. For all analytes, the ranges of recoveries were 81.2–98.2%, with RSDs of 3.2–15.2%, and the LODs were 0.2–0.6 μg kg⁻¹.

     

Simultaneous Determination of Avermectin and Milbemycin Residues in Bovine Tissue by Pressurized Solvent Extraction and LC with Fluorescence Detection

A rapid and sensitive method has been developed for the simultaneous determination of four avermectins and one milbemycin residues in bovine tissue. The isolation of the analytes from muscle and liver samples was accomplished utilizing a pressurized solvent extractor. The optimized extraction procedure using acetonitrile/water (40:60, v/v) as extraction solvent, was automatically carried out at 100 °C and 10 MPa, applying two static cycles for 3 min. The extracts were cleaned up on a C₁₈ solid-phase extraction cartridge and analyzed by liquid chromatography with fluorescence detection after derivatization. Mean recoveries of the five analytes from fortified samples were between 84.8 and 101.8%, with relative standard deviations lower than 10.8%. The limit of detection and quantification were in the ranges of 0.1–0.2 and 0.5–0.6 μg kg^–1, respectively. The application of the newly developed method was demonstrated by analyzing bovine meat samples from market.     

Extraction and preconcentration of 17α-ethynylestradiol as an endocrine-disrupting agent from environmental water samples by a modified magnetic nanosorbent

A rapid, simple and efficient procedure is demonstrated for extraction and determination of an endocrine-disrupting compound, synthetic estrogen, 17α-ethynylestradiol (EE2), in water and wastewater samples via magnetic solid-phase extraction followed by high-performance liquid chromatography coupled with UV detection. The analytical method is based on extraction of EE2 by dispersing magnetic nanoparticles in sample solution for a desired time and then eluting the analytes with an appropriate solvent. The nanoparticles were modified with a hydrophobic material by self-assembling an organosulfur compound (bis-(2,4,4-trimethylpentyl)-dithiophosphinic acid) onto the silver-coated Fe₃O₄ nanoparticles as sorbent. The effects of several parameters, such as amount of sorbent, sample volume, extraction time, ionic strength and desorption conditions, were examined to obtain better efficiency. The optimized methodology exhibited a good linearity between 0.5 and 100 μg L^?1 with a limit of detection (LOD) of 0.3 μg L^?1, and a preconcentration factor of 245 with intra- and inter-day precisions (relative standard deviations) 2.4 and 3.2 %, respectively. The developed method was successfully applied for extraction and determination of EE2 in different real water samples including river water, surface water and influent and effluent of a wastewater treatment plant, and satisfactory results were achieved. The method, which provides a good preconcentration factor, a low LOD and low consumption of the organic solvent, presents a rapid, simple and efficient procedure for determining EE2 in aqueous samples.     

Simultaneous determination of cyromazine,melamine and their biodegradation products by ion-pair high-performance liquid chromatography

An ion-pair high-performance liquid chromatography with ultraviolet detection method for the determination of cyromazine, melamine and its biodegradation products (ammeline, ammelide, cyanuric acid and biuret) was developed. C18 column was utilised to separate the six analytes with a mobile phase consisting of perchloric acid-ammonia solution and acetonitrile, under gradient elution and variable flow rate. The detection wavelengths were 205 nm for cyanuric acid and biuret and 222 nm for cyromazine, melamine, ammeline and ammelide. For analysis of sediment samples, the extraction solution containing acetonitrile, ammonia and water (80:10:10 by volume) was used to extract the analytes from sediment matrix. Using the extraction method for the spiked sediment sample, high linearity of matrix-matched standard curve could be obtained for the six analytes. The method detection limit was 0.1 μg g^?1 for melamine and cyromazine, 0.2 μg g^?1 for ammeline and ammelide, 1.2 μg g^?1 for cyanuric acid and 1.0 μg g^?1 for biuret in sediment matrix. The recoveries of these compounds were 70.1–98.3% and the relative standard deviations were 0.5–4.4%. Finally, the proposed method was successfully applied to the analysis of the sediment sample near the wastewater outlet of a melamine-producing factory.     

Evaluation of preconcentration methods in the analysis of synthetic musks in whole‐water samples

According to the European Water Framework Directive, environmental assessment of organic compounds should be made in whole‐water samples, but due to their hydrophobicity and strong attraction to organic content these compounds can be found bound to suspended particle matter or in the dissolved fraction. In this work, the extraction of musk compounds was studied in whole‐water samples exhibiting different amounts of dissolved organic carbon and suspended particulate matter using polyethersulfone preconcentration technique. Matrix effects in estuarine and wastewater (both influent and effluent) were evaluated for filtered and unfiltered samples. For unfiltered samples, estuarine water exhibited matrix effects <20%, while for effluent it was up to 48% and for influent ranged from 85 to 99%. To compensate matrix effects and determine total concentrations in unfiltered samples, different quantification approaches were tested: the use of deuterated analogues and standard additions. Standard additions provided the best results for unfiltered samples. Finally, filtered and unfiltered samples were analyzed using both polyethersulfone preconcentration and membrane‐assisted solvent extraction and results showed a good agreement between the two methods. In both cases unfiltered samples provided concentrations 1.5–2.6 times higher than filtered samples.     

Simultaneous Derivatization and Dispersive Liquid–Liquid Microextraction for Fatty Acid GC Determination in Water

Simultaneous derivatization and dispersive liquid–liquid microextraction technique for gas chromatographic determination of fatty acids in water samples is presented. One hundred microlitre of ethanol:pyridine (4:1) were added to 4 mL aqueous sample. Then a solution containing 0.960 mL of acetone (disperser solvent), 10 μL of carbon tetrachloride (extraction solvent) and 30 μL of ethyl chloroformate (derivatization reagent) were rapidly injected into the aqueous sample. After centrifugation, 1 μL sedimented phase with the analytes was analyzed by gas chromatography. The effects of extraction solvent type, derivatization, extraction, and disperser solvents volume, extraction time were investigated. The calibration graphs were linear up to 10 mg L^?1 for azelaic acid (R ² = 0.998) and up to 1 mg L^?1 for palmitic and stearic acids (R ² = 0.997). The detection limits were 14.5, 0.67 and 1.06 μg L^?1 for azelaic, palmitic, and stearic acids, respectively. Repeatabilities of the results were acceptable with relative standard deviations (RSD) up to 13%. A possibility to apply the proposed method for fatty acids determination in tap, lake, sea, and river water was demonstrated.     

Occurrence,fate and removal efficiencies of pharmaceuticals in wastewater treatment plants (WWTPs) discharging in the coastal environment of Algiers

In the last few decades, the presence of pharmaceutical products in the environment is known under the name of emerging contaminants. These substances can enter the aquatic environment via different sources, as parent compounds, metabolites or a combination of both. In this work, we have investigated the presence of four pharmaceutical active compounds belonging to the group of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs), in wastewater, surface water and drinking water of Algiers, which have a direct impact on the Mediterranean Sea. The target analytes (ibuprofen (IBU), naproxen (NAP), ketoprofen (KET), and diclofenac (DIC)), were extracted from the water samples by using Solid Phase Extraction Oasis^® HLB Cartridges; the identification and quantification were realized by Gas Chromatography–Mass Spectrometry (GC–MS). To obtain the best resolution and precision, N-methyl-N-(trimethylsilyl) trifluoroacetamide (MSTFA) was used as the derivatization reagent and ibuprofen-d₃ was used as the internal standard. The obtained recoveries were good, ranging from 82% for ketoprofen to 120% for naproxen with relatively small standard deviations (≤20%). The target compounds were detected in wastewater, influent/effluent with concentrations ranging from 155.5 to 6554 ng/L, implicating removal efficiencies of wastewater treatment plants (WWTPs), between 30.3 and 95%. The surface water was also contaminated with pharmaceuticals from 72.9 ng/L for diclofenac to 228.3 ng/L for naproxen. In addition, the occurrence of ibuprofen and ketoprofen in drinking water, at concentrations of 142.1 and 110.9 ng/L, respectively, attracts concerns about possible impacts on human health.     

Occurrence of cytostatic compounds in hospital effluents and wastewaters,determined by liquid chromatography coupled to high-resolution mass spectrometry

The occurrence of 26 commonly used cytostatic compounds in wastewaters was evaluated using an automated solid-phase extraction (SPE) method with liquid chromatography–high-resolution mass spectrometry (LC–HRMS). Detection was optimized using Oasis HLB SPE cartridges at pH 2. Two hospital effluents and their two receiving wastewater treatment plants were sampled over five days. In hospital effluents, eight cytostatics were detected at levels up to 86.2 μg L^?1 for ifosfamide, 4.72 μg L^?1 for cyclophosphamide, and 0.73 μg L^?1 for irinotecan, the three most relevant compounds identified. Cyclophosphamide and megestrol acetate were found in wastewaters at concentrations up to 0.22 μg L^?1 for the latter. The predicted environmental concentrations (PEC) in sewage effluents of ifosfamide (2.4–4.3 ng L^?1), capecitabine (11.5–14.2 ng L^?1), and irinotecan (0.4–0.6 ng L^?1), calculated from consumption data in each hospital, published excretion values for the target compounds, and wastewater elimination rates, were in agreement with experimental values.     

Determination of five polar herbicides in water samples by ionic liquid dispersive liquid-phase microextraction

A simple, rapid and efficient ionic liquid based on dispersive liquid-phase microextraction (IL-DLPME) method was developed for the determination of three triazine and two phenylurea herbicides in water samples. IL (1-hexyl-3-methylimidazolium hexafluorophosphate [C₆MIM][PF₆]) that dispersed completely into the water solution under controlled temperature was used as the extraction solvent. The analytes were easily concentrated into the ionic liquid phase. This technique combined the process of extraction and concentration of the analytes into one step and avoided use of the more common, toxic organic solvents. The factors affecting the extraction efficiency such as the IL volume, sample pH, extraction time, centrifugal time, dissoluble temperature and ionic strength were optimized. The extracts were analyzed by high-performance liquid chromatography (HPLC) coupled with diode array detector (DAD). Under the optimized conditions, recoveries (50.5–109.1%) were obtained for the target analytes in water samples. The calibration curves were linear and the correlation coefficient ranged from 0.9947 to 0.9973 in the concentration levels of 5–100 μg L^?1. The relative standard deviations (RSDs, n?=?5) were 6.80–10.78%. The limit of detections (LODs) for the five polar herbicides were between 0.46 μg L^?1 and 0.89 μg L^?1.     

Large Volume Headspace Analysis Using Solid-Phase Microcolumn Extraction

A rapid and simple large volume headspace (HS) sampling technique termed headspace solid-phase microcolumn extraction (HS-SPMCE) is described. HS gas above a liquid or solid sample is aspirated by attaching a gas-tight syringe onto a glass thermal desorption tube filled with Tenax sorbent. The trapped analytes are recovered by thermal desorption for gas chromatography–mass spectrometry (GC–MS) analysis. Benzene, toluene, ethylbenzene and the xylene isomers (BTEX) are used as model compounds to demonstrate the application of the extraction procedure for water samples. The results of the tests of the effect of agitation time and aspiration rate on recovery of the analytes show a good robustness of the method. BTEX are determined in the linear range from 0.5 to 50.0 μg L^?1 with limits of detection (3 σ) ranging within 0.09–0.14 μg L^?1 (MS was in scan mode). The method provides a good repeatability (RSD < 9%) and only a negligible carryover effect was observed ( ≤0.05%) when analysing BTEX at concentration 50.0 μg L^?1.     

Gas chromatographic–mass spectrometric fragmentation study of phytoestrogens as their trimethylsilyl derivatives: Identification in soy milk and wastewater samples

An analytical method for the identification of eight plant phytoestrogens (biochanin A, coumestrol, daidzein, equol, formononetin, glycitein, genistein and prunetin) in soy products and wastewater samples was developed using gas chromatography coupled with ion trap mass spectrometry (GC/MS–MS). The phytoestrogens were derivatized as their trimethylsilyl ethers with trimethylchlorosilane (TMCS) and N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA). The phytoestrogens were isolated from all samples with liquid–liquid extraction using ethyl acetate. Daidzein-d₄ and genistein-d₄ labeled standards were used as internal standards before extraction and derivatization. The fragmentation patterns of the phytoestrogens were investigated by isolating and fragmenting the precursor ions in the ion-trap and a typical fragmentation involved the loss of a methyl and a carbonyl group. Two characteristic fragment ions for each analyte were chosen for identification and confirmation. The developed methodology was applied to the identification and confirmation of phytoestrogens in soy milk, in wastewater effluent from a soy-milk processing plant, and in wastewater (influent and effluent) from a treatment plant. Detected concentrations of genistein ranged from 50,000 μg/L and 2000 μg/L in soy milk and in wastewater from a soy-plant, respectively, to 20 μg/L and <1 μg/L for influent and effluent from a wastewater treatment plant, respectively.     

Optimization of a SPME/GC/MS Method for the Simultaneous Determination of Pharmaceuticals and Personal Care Products in Waters

A headspace solid phase microextraction (HS-SPME) method coupled with gas chromatography and MS detection (GC/MS) was optimized for the simultaneous determination of 21 target Pharmaceuticals and Personal Care Products (PPCPs) in water samples. The analytes included fragrances, UV-filters, antiseptics, estrogens, anti-inflammatory drugs, and pesticides. An on-fiber SPME derivatization, using silyl reagents, was performed for the analysis of more polar acidic compounds. An experimental design approach was applied to systematically investigate and optimize the operative parameters affecting the extraction recovery, namely: extraction temperature and time, derivatization time, desorption temperature and time. The optimum operating conditions were: extraction time of 125?min at a temperature of 40?°C; derivatization time of 30.5?min; desorption time of 2?min at a temperature of 300?°C. Under these conditions, good reproducibility was assessed as RDS% values ≤10% for underivatized PPCPs and ≤20% for derivatized compounds. The method detection limits (LOD) were between 0.7 and 9.0?ng?L^?1, with the highest values in the range 2.5–9.0?ng?L^?1 for the derivatized analytes. Method accuracy was evaluated on spiked tap water samples: recoveries varied from 85 to 103% and from 75 to 110% for non-derivatized and derivatized compounds, respectively.     

Application of Single Drop Extraction (SDE) Gas Chromatography Method for the Determination of Carbonyl Compounds in Spirits and Vodkas

Abstract

The application of single drop extraction (SDE) for isolation and enrichment of carbonyl compounds after derivatization with O‐(2,3,4,5,6‐pentafluorobenzyl)hydroxylamine in spirits and vodkas is discussed. The optimal parameters (extraction volume, drop volume, content of ethyl alcohol, sample volume, temperature and time of extraction) for isolation and preconcentration of C₁–C₆ aldehydes from alcoholic matrices were established. The developed SDE‐gas chromatography (GC)‐electron capture detection (ECD), an extraction method, allows the determination of low molecular aldehydes at level lower than 1 µg dm^?3. The overall analysis time without derivatization is 35 minutes. The procedure was applied for the determination of aldehydes in real alcoholic beverages (vodkas). The simplicity and cost‐effectiveness of the proposed procedure makes it a good alternative to solid phase microextraction (SPME) and other more labor‐intensive methods.