Quantification of perphenazine in eurasian otter (Lutra lutra lutra) urine samples by gas chromatography-mass spectrometry

Assessment of contaminants of emerging concern in European apex predators and their prey by LC-QToF MS wide-scope target analysis

Apex predators are good indicators of environmental pollution since they are relatively long-lived and their high trophic position and spatiotemporal exposure to chemicals provides insights into the persistent, bioaccumulative and toxic (PBT) properties of chemicals. Although monitoring data from apex predators can considerably support chemicals' management, there is a lack of pan-European studies, and longer-term monitoring of chemicals in organisms from higher trophic levels. The present study investigated the occurrence of contaminants of emerging concern (CECs) in 67 freshwater, marine and terrestrial apex predators and in freshwater and marine prey, gathered from four European countries. Generic sample preparation protocols for the extraction of CECs with a broad range of physicochemical properties and the purification of the extracts were used. The analysis was performed utilizing liquid (LC) chromatography coupled to high resolution mass spectrometry (HRMS), while the acquired chromatograms were screened for the presence of more than 2,200 CECs through wide-scope target analysis. In total, 145 CECs were determined in the apex predator and their prey samples belonging in different categories, such as pharmaceuticals, plant protection products, per- and polyfluoroalkyl substances, their metabolites and transformation products. Higher concentration levels were measured in predators compared to prey, suggesting that biomagnification of chemicals through the food chain occurs. The compounds were prioritized for further regulatory risk assessment based on their frequency of detection and their concentration levels. The majority of the prioritized CECs were lipophilic, although the presence of more polar contaminants should not be neglected. This indicates that holistic analytical approaches are required to fully characterize the chemical universe of biota samples. Therefore, the present survey is an attempt to systematically investigate the presence of thousands of chemicals at a European level, aiming to use these data for better chemicals management and contribute to EU Zero Pollution Ambition.

LC-MS-MS Determination of 25 Antipsychotic Drugs and Metabolites in Urine for Medication Compliance Monitoring

A liquid chromatography-tandem mass spectrometry (LC-MS-MS) method was developed for 25 antipsychotic drugs and their metabolite in urine for monitoring medication compliance of mentally disordered criminals on probation. Target compounds were extracted with a solid-phase extraction technique using a newly developed hydrophilic-lipophilic balanced sorbent to remove interferences and minimize the matrix effect (ME). Extracted sample was injected into the LC-MS-MS with an electrospray ionization source in positive mode and multiple-reaction monitoring mode. The analytes were separated and detected within 10 minutes using a reversed-phase column with a gradient elution method using 0.1% formic acid in water and 0.1% formic acid in methanol as mobile phase. The validation parameters were evaluated as follows: selectivity, limit of detection, lower limit of quantification (LLOQ), linearity, accuracy and precision, stability, dilution integrity, recovery (RE), ME and process efficiency (PE). The LLOQs were 0.1 to 2.0 ng/mL, and determination coefficients of the calibration curve were above 0.9943 over the concentration ranges. The intra-and inter-day accuracy ranged from -10.4% to 9.9% and from -9.6% to 9.4%, while the intra-and inter-day precision were within 10.7% and 9.9%. The bench-top and long-term stability ranged from 92.1% to 109.5% and 88.7% to 111.6%, respectively. The reproducibility of auto-sampler stability was <10% for all analytes. The accuracy and precision of dilution integrity ranged from -11.7% to 10.5% and 0.4% to 9.9%, respectively. The relative standard deviation of RE and ME was from 0.6% to 6.6% and 0.5% to 3.9%, respectively, while that of PE was 1.3% to 4.5%. The developed LC-MS-MS method for medication compliance monitoring was successfully applied to urine samples from mentally disordered probationers and determined to be one of effective ways for preventing the recurrence of mentally disordered crimes.

Electrooxidation and determination of perphenazine on a graphene oxide nanosheet-modified electrode

The electrochemical behavior of perphenazine was investigated on a graphene oxide nanosheet-modified glassy carbon electrode in a phosphate buffer solution at pH 7.4.

Highly sensitive determination of perphenazine on a carbon nanocomposite ionic liquid electrode

A multi-walled carbon nanotube–ionic liquid nanocomposite was fabricated for the electrochemical detection of perphenazine, suitable for the analysis of pharmaceuticals and blood serum samples.

HPLC quantification of perphenazine in sheep plasma: Application to a pharmacokinetic study

A high performance liquid chromatographic (HPLC) method for the determination of perphenazine (PPZ) in sheep plasma was developed and validated. The separation was achieved using a 5 microm C18 column (125 mm x 4 mm) with a mobile phase composed of acetonitrile and an aqueous solution of H(3)PO(4) and TBA (inverse gradient). The flow rate was 1.5 mL/min and the UV detection was performed at 258 nm. The method was validated with respect to linearity, intra and inter-day precision and accuracy, limit of quantification, limit of detection and storage stability. This method was used to perform a pilot pharmacokinetic study of PPZ after subcutaneous administration to one ewe.

Kinetic spectrophotometric method for determination of perphenazine based on monitoring the oxidation intermediate by applying a stopped-flow technique

A novel and high-sensitive stopped-flow kinetic spectrophotometic method for the determination of perphenazine based on monitoring the variation of absorbance of the intermediate within a few seconds has been developed. The optimum conditions for various parameters on which the forming of the intermediate depends, were investigated. It was found that the initial reaction rate increased linearly with an increase in the perphenazine concentration in the range from 1.0 x 10(-5) to 1.6 x 10(-4)M. The detection limit was calculated to be 5.3 x 10(-6)M. The kinetics of the reaction was established by the aid of single-mixing or double-mixing stopped-flow techniques, a successive reaction model was proposed to analyze and simulate the reaction. The influence of both ascorbic acid and NADH on the time courses was also investigated.

Stability studies of selected doping agents in urine: caffeine

The stability of caffeine in urine samples has been studied. A high-performance liquid chromatography (HPLC) method for the quantification of caffeine in urine samples was validated for that purpose. The method consists of a liquid-liquid extraction at alkaline pH with chloroform-2-propanol (9:1, v/v) with a salting out effect. 7-Ethyltheophylline was used as internal standard (ISTD). Analyses were performed with an Ultrasphere ODS C18 column using water/acetonitrile (90:10, v/v) as a mobile phase at a flow rate of 1 ml/min. Ultraviolet absorption at 280 nm was monitored. Extraction recoveries for caffeine and 7-ethyltheophylline were 81.4+/-6.0 and 87.3+/-5.7%, respectively. The calibration curves were demonstrated to be linear in the working range of 6-30 microg/ml (r2>0.990). The limit of detection and the limit of quantitation were estimated as 0.7 and 2.0 microg/ml, respectively. Precisions in the range of 1.5-9.2 and 4.1-5.8% were obtained in intra- and inter-assay studies, respectively, using control samples containing 10, 14 and 26 microg/ml of caffeine. Accuracies ranging from 2.9 to 7.4% for intra-assay experiments, and from 3.9 to 5.4% in inter-assay studies were obtained. Stability of caffeine in urine samples was evaluated after long- and short-term storage at different temperature conditions. The batches of spiked urine were submitted to sterilization by filtration. No adsorption of the analyte on filters was observed. Before starting stability studies, batches of reference materials were tested for homogeneity. For long-term stability testing, caffeine concentration in freeze-dried urine stored at 4 degrees C and in liquid urine samples stored at 4, -20, -40 and -80 degrees C was determined at several time intervals for 18 months. For short-term stability testing, caffeine concentration was evaluated in liquid urine stored at 37 degrees C for 7 days. The effect of repeated freezing (at -20 degrees C) and thawing was also studied for up to three cycles. The stability of caffeine was also evaluated in non-sterile samples stored at -20 degrees C for 18 months. No significant loss of the compound was observed at any of the investigated conditions.

Amperometric detection of perphenazine at a carbon fiber micro-disk bundle electrode by capillary zone electrophoresis

A simple method for determination of perphenazine by capillary zone electrophoresis with amperometric detection is described. The optimum conditions of separation and detection are 1.50 x 10(-3) mol/l Na(2)B(4)O(7)-1.0 x 10(-3) mol/l NaOH (pH 9.9) for the buffer solution, 18 kV for the separation voltage, 5 kV and 5 s for the injection voltage and the injection time, and 0.80 V versus saturated calomel electrode for the detection potential, respectively. The limit of detection is 5.0 x 10(-8) mol/l or 44 amol (S/N=3). The linear range of the calibration curve is 1.00 x 10(-7) to 1.00 x 10(-4) mol/l. The relative standard deviation is 1.5% for the migration time and 2.9% for the electrophoretic current at peak maximum. The method is applied to the determination of perphenazine in human urine.