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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.

A simple and rapid pretreatment method based on effervescent tablet-assisted dispersive liquid–liquid microextraction was introduced for the determination of three fungicides (azoxystrobin, chlorothalonil, and cyprodinil) in fruit juice samples followed by liquid chromatography–ultraviolet detection.

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 µL 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 µg 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%.

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.

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.