In-syringe homogeneous liquid-phase microextraction followed by filtration-based phase separation for on-site extraction of chloroanilines from water samples.

This study introduces a new in-syringe homogeneous liquid-phase microextraction method for the rapid on-site extraction of chloroanilines from water samples. Extraction was performed using a plastic syringe, eliminating the use of any electrical power source. Di-(2-ethylhexyl) phosphoric acid (DEHPA) served as the extractant. The process initially involved dissolving DEHPA in an alkaline solution to obtain a homogeneous solution. Subsequently, the sodium salt of DEHPA was precipitated by salting-out, and the resulting heterogeneous mixture was filtered using a syringe filter. The precipitate containing the analytes was then dissolved in methanol for analysis by high-performance liquid chromatography. Under optimal conditions, extraction recovery for chloroanilines ranged from 26% to 71%. Method linearity was evaluated within a concentration range of 1.0-100 µg/L, resulting in coefficients of determination exceeding 0.9987 for all analytes. Method detection limits ranged from 0.28 to 0.41 µg/L. Intra and inter-day precision values were below 9.5% and 10.8%, respectively. The developed method was applied to determine chloroanilines in real waters, yielding acceptable recoveries ranging from 80% to 109% for spiked tap, rain, and stream waters. Additionally, the method was successfully employed for on-site extraction of target contaminants, demonstrating no statistically significant differences compared to laboratory results.

Dispersive liquid-liquid microextraction method combined with sugaring-out homogeneous liquid-liquid extraction for the determination of some pesticides in molasses samples.

In this study, a sensitive analytical method was developed to determine some pesticides (cyprodinil, trifloxystrobin, prometryn, propachlor, fenitrothion, chlorpyrifos, profenofos, and phosalone) in molasses samples. Pesticides were extracted from samples by dispersive liquid-liquid microextraction method combined with sugaring-out homogeneous liquid-liquid extraction and determined by gas chromatography-mass spectrometry analysis. In this method, pesticides in molasses samples were first extracted using a water-miscible solvent (acetonitrile) in the sugaring-out homogeneous liquid-liquid extraction stage. The sugar in the ratio of 84-88% naturally contained in the molasses sample enabled phase separation in the acetonitrile-water homogeneous mixture. Then acetonitrile phase containing pesticides was used as dispersing solvent in the second step of the process. Under the specified optimum conditions, the limit of detection was calculated between 0.8-6.1 ng/g and the limit of quantification was in the range of 2.5-20 ng/g. The relative standard deviation values of molasses samples containing 150 ng/g of each analyte were found to be lower than 4.9% intra-day and 5.6% for inter-day. This validated method has been successfully applied to different types of molasses.

Vortex-Assisted Deep Eutectic Solvent-Based Liquid-Liquid Microextraction for the Analysis of Alkyl Gallates in Vegetable Oils.

This study investigates the feasibility of using hydrophilic deep eutectic solvent (DES) as green and effective extractant for the extraction and preconcentration of alkyl gallates from vegetable oils. In a typical experiment, 120 αL of choline chloride:ethylene glycol DES was added to 1.0 g of oil sample which was previously diluted with 1 mL of n-hexane. The extraction was accelerated by vortex stirring of the two phases. At this stage, hydrogen bonding interactions between the phenyl hydroxyls of alkyl gallates and chloride anion of choline salt were likely the main forces driving the extraction. After extraction, the analytes in the DES phase were separated and determined by high-performance liquid chromatography with ultraviolet detection. The method detection limits for propyl gallate and octyl gallate were 2.1 and 4.6 αg kg-1, respectively. The precision of the method varied between 4.6-6.4% (intra-day) and 5.4-7.5% (inter-day). The recoveries (accuracies) obtained from spiked vegetable oil samples were in the range of 78-106%.

Miniaturized matrix solid-phase dispersion coupled with supramolecular solvent-based microextraction for the determination of paraben preservatives in cream samples.

An analytical method is presented for the determination of paraben preservatives in semisolid cream samples by matrix solid-phase dispersion combined with supramolecular solvent-based microextraction. Due to the oily and sticky nature of the sample matrix, parabens were first extracted from the samples by matrix solid-phase dispersion using silica as sorbent material with a clean-up performed with tetrahydrofuran in the elution step. The eluate (500 µL), 1-decanol (120 µL), and water (4.4 mL) were then mixed in a polyethylene pipette to form supramolecular solvent. Finally, the analytes in the supramolecular solvent were separated and determined by liquid chromatography with ultraviolet detection. Under optimal extraction conditions, the extraction recoveries of the studied compounds were obtained in the range of 63-83%. The limits of detection for the analytes were between 0.03 and 0.04 µg/g. The precision of the method varied between 4.0-6.7 (intraday) and 6.2-7.9% (interday). Finally, the optimized procedure was applied to the determination of the target preservatives in a variety of cream samples (diaper rash, skin allergy, face and hand moisturizing) with satisfactory recoveries (86-102%).

Determination of biogenic amines in licorice (Glycyrrhiza glabra) by ion-pair extraction and liquid chromatography-tandem mass spectrometry.

BACKGROUND: Ion-pair extraction combined with liquid chromatography-tandem mass spectrometry method has been proposed for the determination of biogenic amines in licorice samples. RESULTS: Limit of detection and limit of quantitation for the biogenic amines were 1.4-2.7 and 4.7-9.1 ng mL-1 , respectively. Relative standard deviations based on five replicate extraction of 100 ng mL-1 of each biogenic amine were <4.7% for intra-day and 7.4% for inter-day precision. The method described in this study has been shown to be in accordance with satisfactory accuracy and good reproducibility for the quantitative determination of biogenic amines in licorice samples. Nine biogenic amines (putrescine, cadaverine, histamine, spermine, spermidine, tyramine, tryptamine, agmatine and phenylethylamine) were detected in licorice samples and total biogenic amine concentrations were determined at 369 ng mL-1 in fresh and 3532 ng mL-1 in non-fresh licorice samples. Putrescine was found at the highest concentrations to be up to 704 ng mL-1 in all the analyzed samples, followed by tyramine (675 ng mL-1 ) and tryptamine (282 ng mL-1 ). Putrescine, tyramine and spermine concentrations were dramatically increased, whereas agmatine concentration was significantly decreased, in non-fresh licorice samples compared to fresh ones. CONCLUSION: The consumption of freshly prepared licorice is recommended because of the relatively low concentration of total biogenic amines. © 2016 Society of Chemical Industry.

pH-assisted homogeneous liquid-liquid microextraction using dialkylphosphoric acid as an extraction solvent for the determination of chlorophenols in water samples.

In this study, a new pH-assisted homogeneous liquid-liquid microextraction combined with HPLC with UV detection was developed for the determination of chlorophenols in water samples. In this approach, bis(2-ethylhexyl) phosphate was used for the first time as the low-density extraction solvent. In particular, 60 µL of bis(2-ethylhexyl) phosphate was injected into the sample solution (5 mL) and dissolved completely in the sample solution while the pH was increased to 9. Afterwards, the pH of the sample solution was lowered to 1, and a cloudy solution was formed. At this stage, hydrophobic interactions between the analytes and the long double hydrocarbon chains of extraction solvent were expected to be the main forces driving extraction. A series of parameters that influence extraction were investigated systematically. Under the optimized conditions, the LODs and LOQs for the chlorophenols were 1.4-2.7 and 4.7-9.1 ng/mL, respectively. RSDs based on five replicate extraction of 100 ng/mL of each chlorophenols were <4.7% for intraday and 7.4% for interday precision. This method has been also successfully applied to analyze real water samples at two different spiked concentrations, and satisfactory recoveries were achieved.

Biomonitoring of polycyclic aromatic hydrocarbons in urban and industrial environments of the Western Black Sea Region, Turkey.

This research was carried out in the cities of Zonguldak and Eregli, which have been characterized as urban and industrial environments of the Western Black Sea Region, Turkey, in order to assess the contamination of polycyclic aromatic hydrocarbons (PAHs) using mosses as biomonitors. The methodology involved the collection of moss samples (Hypnum cupressiforme), ultrasonic extraction with dichloromethane, cleanup using silica gel and analysis by liquid chromatography with ultraviolet detection. The total PAH concentrations ranged from 78.1 to 1693.5 ng g(-1) in Zonguldak and from 15.2 to 275.1 ng g(-1) in Eregli. The total PAH concentration in Eregli was about six times lower than that in Zonguldak, revealing the importance of switching from coal to natural gas in residential heating. The diagnostic ratios and the correlation analysis have indicated that coal combustion and traffic emissions were the major PAH sources at both sites. The contour maps were constructed for the determination of spatial distributions of total PAHs, and it was shown for Zonguldak as well as for Eregli that the PAH pollution was much more predominant in highly populated regions. Moving away from the city centres, a gradual decrease in PAH pollution rates was observed.

Low density solvent-based dispersive liquid-liquid microextraction for the determination of synthetic antioxidants in beverages by high-performance liquid chromatography.

A simple and efficient method was established for the determination of synthetic antioxidants in beverages by using dispersive liquid-liquid microextraction combined with high-performance liquid chromatography with ultraviolet detection. Butylated hydroxy toluene, butylated hydroxy anisole, and tert-butylhydroquinone were the antioxidants evaluated. Experimental parameters including extraction solvent, dispersive solvent, pH of sample solution, salt concentration, and extraction time were optimized. Under optimal conditions, the extraction recoveries ranged from 53 to 96%. Good linearity was observed by the square of correlation coefficients ranging from 0.9975 to 0.9997. The relative standard deviations ranged from 1.0 to 5.2% for all of the analytes. Limits of detection ranged from 0.85 to 2.73 ng mL(-1). The method was successfully applied for determination of synthetic antioxidants in undiluted beverage samples with satisfactory recoveries.

A simple solvent collection technique for a dispersive liquid-liquid microextraction of parabens from aqueous samples using low-density organic solvent.

A simple technique for the collection of an extraction solvent lighter than water after dispersive liquid-liquid microextraction combined with high-performance liquid chromatography with ultraviolet detection was developed for the determination of four paraben preservatives in aqueous samples. After the extraction procedure, low-density organic solvent together with some little aqueous phase was separated by using a disposable glass Pasteur pipette. Next, the flow of the aqueous phase was stopped by successive dipping the capillary tip of the pipette into anhydrous Na(2)SO(4). The upper organic layer was then removed simply with a microsyringe and injected into the high-performance liquid chromatography system. Experimental parameters that affect the extraction efficiency were investigated and optimized. Under optimal extraction conditions, the extraction recoveries ranged from 25 to 86%. Good linearity with coefficients with the square of correlation coefficients ranging from 0.9984 to 0.9998 was observed in the concentration range of 0.001-0.5 µg/mL. The relative standard deviations ranged from 4.1 to 9.3% (n = 5) for all compounds. The limits of detection ranged from 0.021 to 0.046 ng/mL. The method was successfully applied for the determination of parabens in tap water and fruit juice samples and good recoveries (61-108%) were achieved for spiked samples.

Gas-particle partitioning and seasonal variation of polycyclic aromatic hydrocarbons in the atmosphere of Zonguldak, Turkey.

Atmospheric concentrations and gas-particle partition coefficients were determined for polycyclic aromatic hydrocarbons (PAHs) in the atmosphere of Zonguldak, Turkey between May 2007 and April 2008. Total concentrations of PAHs ranged from 0.52ngm(-3) to 636ngm(-3) in the particle phase and from 5.60ngm(-3) to 725ngm(-3) in the gas phase. The annual mean concentrations of PAHs in the particle and gas phase were found to be 114ngm(-3) and 184ngm(-3), respectively. Significant seasonal variations of particle and gas phase PAH concentrations were observed with higher levels during cold period. The distribution of PAHs between the particle and gas phase was investigated and it was found that three ring PAHs were associated primarily with the gas phase, four ring PAHs were distributed almost equally between the two phases and five and six ring PAHs were mainly associated with the particle phase. Gas-particle partition coefficients (K(p)) of PAHs have been calculated and correlated with their subcooled liquid vapor pressures (P(L)º). The slopes (m(r)) varied from -0.63 to -0.23 were far from the theoretical value (-1) due to the short distance between the sampling point and the emission sources. The relationships between temperature and gas phase partial pressures of PAHs were examined using the Clausius-Clapeyron equation and the obtained positive slopes indicated that PAH concentrations increased with decreasing air temperature as a result of high dominance of local emissions.

Meteorological variations of PM2.5/PM10 concentrations and particle-associated polycyclic aromatic hydrocarbons in the atmospheric environment of Zonguldak, Turkey.

Airborne particulate matter (PM(2.5) and PM(10)) concentrations were measured in Zonguldak, Turkey from January to December 2007, using dichotomous Partisol 2025 sampler. Collected particulate matter was analyzed for 14 selected polycyclic aromatic hydrocarbons (PAHs) by high-performance liquid chromatography with fluorescence detection (HPLC-FL). The seasonal variations of PM(2.5) and PM(10) concentrations were investigated together with their relationships with meteorological parameters. The maximum daily concentrations of PM(2.5) and PM(10) reached 83.3 microg m(-3) and 116.7 microg m(-3) in winter, whereas in summer, they reached 32.4 microg m(-3) and 66.7 microg m(-3), respectively. Total concentration of PM(10)-associated PAHs reached 492.4 ng m(-3) in winter and 26.0 ng m(-3) in summer times. The multiple regression analysis was performed to predict total PM(2.5)- and PM(10)-associated PAHs and benzo(a)pyrene-equivalent (BaPE) concentrations with respect to meteorological parameters and particulate mass concentrations with the determination coefficients (R(2)) of 0.811, 0.805 and 0.778, respectively. The measured mean values of concentrations of total PM(2.5)- and PM(10)-associated PAHs were found to be 88.4 ng m(-3) and 93.7 ng m(-3) while their predicted mean values were found to be 92.5 ng m(-3) and 98.2 ng m(-3), respectively. In addition, observed and predicted mean concentration values of PM(2.5)-BaPE were found to be 14.1 ng m(-3) and 14.6 ng m(-3). The close annual mean concentrations of measured and predicted total particulate related PAHs imply that the models can be reliably used for future predictions of particulate related PAHs in urban atmospheres especially where fossil fuels are mainly used for heating.

Treatment of severe amitriptyline intoxication with plasmapheresis.

Tricyclic antidepressant poisoning is one of the most common causes of serious intoxication. Here, we report a 2-year-old girl with severe amitriptyline (70 mg/kg) intoxication. She was in comatose, had generalized tonic clonic seizure, ventricular tachycardia, and wide QRS complexes. Although she did not respond to classical therapies, very good clinical response to plasmapheresis was obtained and she developed no complications. Thus, plasmapheresis may be an effective treatment modality in poisoning with drugs, which bind to plasma proteins with high affinity.

Particle-associated polycyclic aromatic hydrocarbons in the atmospheric environment of Zonguldak, Turkey.

Airborne fine (PM(2.5)) and coarse (PM(2.5-10)) particulate matter was collected from January to December in 2007 in Zonguldak, Turkey using dichotomous Partisol 2025 sampler. Fourteen selected polycyclic aromatic hydrocarbons (PAHs) in particulate matter were determined simultaneously by high-performance liquid chromatography with fluorescence detection (HPLC-FL) and seasonal distributions were examined. The source identification of PAHs in airborne particulates was performed by principal component analysis (PCA) in combination with diagnostic ratios. The predominant PAHs determined in PM(2.5) were pyrene, fluoranthene, benzo[a]anthracene, chrysene, benzo[b]fluoranthene and benzo[a]pyrene. The total concentrations of PAHs were up to 464.0 ng m(-3) in fine and 28.0 ng m(-3) in coarse fraction in winter, whereas in summer times were up to 22.9 and 3.0 ng m(-3) respectively. Approximately 93.3% of total PAHs concentration was determined in PM(2.5) in winter and 84.0% in summer. The concentration levels of PAHs fluctuate significantly within a year with higher means and peak concentrations in the winter compared to that of summer times. Higher benzo(a)pyrene-equivalent (BaPE) concentrations of PAHs were obtained for PM(2.5) especially in winter. The results obtained from PCA in combination with diagnostic ratios revealed that coal combustion and vehicle emissions were the major pollutant sources for both PM(2.5) and PM(2.5-10) associated PAHs in studied area. Two principal components for PM(2.5) and three for PM(2.5-10) were identified and these accounted for 89.4 and 85.2% of the total variance respectively. The emissions from coal combustion were estimated to be the main source of PAHs in the ambient air particulates with contributions of 80.8% of total variance for PM(2.5) and 53.8% for PM(2.5-10).