Streamlined Water-Leaching Preconcentration Method As a Novel Analytical Approach and Its Coupling to Dispersive Micro-Solid-Phase Extraction Based on Synthetically Modified (Fe/Co) Bimetallic MOFs.

The streamlined water-leaching preconcentration method is introduced as a novel preconcentration method in this study. The approach has many benefits including low consumption of organic solvent and deionized water and operation time, energy-saving, no need for dispersion or evaporation, and implementation of more efficient preconcentration. Also, a methodological study was done on the synthesis of (Fe/Co) bimetallic-organic framework that eased the synthesis procedure, decreased its time, and enhanced its analytical performance by increasing its surface area, total pore volume, and average pore diameter parameters. To perform the extraction, bi-MOF particles were added into the solution of interest enriched with sodium sulfate. After vortexing to adsorb the analytes, centrifugation isolated the sorbent particles. A microliter-volume of acetonitrile and 1,2-dibromoethane mixture was used for desorption aim via vortexing. After the separation of the organic phase and transferring it into a conical bottom glass test tube, a milliliter volume of sodium chloride solution was applied to leach the organic phase. A gas chromatograph equipped with a flame ionization detector was applied for the injection of the extracted phase. The method was applied for the extraction and preconcentration of some pesticides from juice samples. Wide linear ranges (5.44-1600 µg L-1), low relative standard deviations (3.1-4.5% for intra- (n = 6) and 3.5-5.2% for interday (n = 4) precisions), high extraction recoveries (61-95%), enrichment factors (305-475), and low limits of detection (0.67-1.65 µg L-1) and quantification (2.21-5.44 µg L-1) were obtained for the developed method.

Extraction and preconcentration of parabens from the human follicular fluid through dispersive micro solid phase extraction using microporous MIL-68 (In) followed by in-situ effervescence-boosted dispersive liquid-liquid microextraction.

For the first time in this study, a microextraction method was developed to perform follicular fluid safety assessment analysis. The drastic importance of follicular fluid safety on the proper nourishment and development of oocytes caused the development of the present method. Since women are regularly exposed to parabens through cosmetics, healthcare, and hygienic products, the infection of body fluids is probable in long-term exposures. Also, for the first time, MIL-68 (In) was applied in an analytical method. Moreover, a new method called in-situ effervescence-boosted dispersive liquid-liquid microextraction was adopted for the simultaneous derivatization and preconcentration of the target parabens. To perform the method, 25 mg of MIL-68 (In) was dispersed into the solution of follicular fluid by vortexing. Then, 1.0 mL of 2-propanol was used to elute the analytes from the absorbent via vortexing. The analyte-enriched organic phase was mixed with 100 µL of acetic anhydride (derivatization agent) and 27 µL 1,2-dibromoethane (extraction solvent) which was swiftly injected into a sodium carbonate solution. Following the centrifugation, the extraction solvent was sedimented at the bottom of a conical bottom glass test tube and an aliquot of it was injected into a gas chromatograph equipped with a flame ionization detector. Wide linear ranges (120-25000 µg L-1), satisfactory extraction recoveries (31-79%) and enrichment factors (31-79), and appreciable limits of detection (7-36 µg L-1) and quantification (25-120 µg L-1) were recorded. The high surface area of MIL-68 (In) (608.82 m2 g-1) and its significantly low average pore diameter (13.829 A°) provide an ideal platform for the extraction of parabens from the complex matrix of follicular fluid.

A cross-sectional study on metoprolol concentrations in various biological samples and their inter-correlations.

BACKGROUND: Concentrations of metoprolol in exhaled breath condensate (EBC) have not been investigated. Herein, we aim to determine the metoprolol levels in EBC, plasma, and urine samples. METHODS: Biological samples were collected from 39 patients receiving metoprolol. Metoprolol was determined using liquid chromatography mass spectrometery. The obtained metoprolol levels in biological fluids were investigated for possible inter-correlations. RESULTS: Acceptable linearity was obtained with coefficient of determinations equal to 0.9998, 0.9941, and 0.9963 for EBC, plasma, and urine samples, respectively. The calibration curves were linear in the ranges of 0.6-500, 0.4-500, and 0.7-10,000 µg·L- 1 regarding EBC, plasma, and urine samples, respectively. The detection and quantification limits were (0.18, 0.12, and 0.21 µg·L- 1) and (0.60, 0.40, and 0.70 µg·L- 1) for EBC, plasma, and urine samples, respectively. The relative standard deviations for the intra- and inter-day replications were obtained between 5.2 and 6.1 and 3.3-4.6%, respectively. The obtained mean metoprolol levels in EBC, plasma, and urine samples of 39 patients were 5.35, 70.76, and 1943.1 µg·L- 1. There were correlations between daily dose and plasma and urinary concentrations of metoprolol in the investigated samples, whereas no significant correlation was observed for daily dose and EBC levels. The correlation among plasma-urine levels was significant, however, the non-significant correlation was obtained between plasma and EBC concentrations. CONCLUSION: Metoprolol levels varied widely due to the metabolic pattern of the Azeri population, different dosages received by the patients, formulation effects, age, sex, and interactions with the co-administered drugs. A poor correlation of EBC-plasma concentrations and a significant correlation of plasma-urine concentrations were observed. Further investigations are required to provide the updated services to personalized medicine departments.