Simultaneous determination of carbonyl compounds related to thermal treatment and oxidative stability of infant formulas by gas-diffusion microextraction and high-performance liquid chromatography with ultraviolet detection.

Infant formulae are the only possible alternative to breastfeeding during the first year of life, so it is crucial to assure their innocuousness. Infant formula undergoes heat treatments to ensure safety and shelf life. However, such processes impact health as they lead to the formation of malondialdehyde, acrolein, and α-dicarbonyl compounds, related to Maillard reaction.

Development of a QuEChERS method for simultaneous analysis of 3-Monochloropropane-1,2-diol monoesters and Glycidyl esters in edible oils and margarine by LC-APCI-MS/MS.

A simple, fast and effective direct method based on HPLC-APCI-QqQ-MS/MS has been developed to simultaneously determine four 3-monochloropropane-1,2-diol monoesters (3-MCPDE) esterified with palmitic, linoleic, stearic, and oleic acid, and two glycidyl esters (GE) with palmitic and oleic acid in margarine and olive oil using a QuEChERS approach. Factors affecting the efficiency of the extraction process were assessed, including type and amount of salt, extraction solvent, test portion amount, and clean-up sorbent. The analytical method was validated according to Food and Drug Administration (FDA) guidelines using matrix-matched calibration with internal standards and showed good results in terms of linearity (r > 0.

Ultrasound-assisted enzymatic indirect determination of total 3-monochloropropane-1,2-diol esters in canned fish oil fraction.

A novel, fast, and cost-effective indirect enzymatic method was successfully developed to assess the total 3-monochloropropane-1,2-diol (3-MCPD) in canned food's oil fraction by the action of Burkholderia cepacia lipase. The total 3-MCPD were derivatized with n-Heptafluorobutyrylimidazole (HFBI) for GC-MS analysis during dispersive liquid-liquid microextraction (DLLME). An asymmetrical 21//8 screening design was used to study the influence of critical factors on the method's effectiveness.

Determination of synthetic opioids in oral fluid samples using fabric phase sorptive extraction and gas chromatography-mass spectrometry.

New psychoactive substances (NPS) continue to emerge in the drug market every year, becoming a global threat to public health and safety. These compounds are mostly synthetic cannabinoids and designer cathinones. However, synthetic opioids have appeared on the recreational drug markets in recent years, particularly fentanyl and its derivatives ("fentanyls").

Cyclodextrin-functionalized cellulose filter paper for selective capture of diclofenac.

An environmentally friendly and low-cost material based on cellulose filter paper modified with β-cyclodextrin (β-CD) was designed to uptake and elute drugs for water purification. To carry out the work, a β-CD derivative was first obtained through reaction of β-CD with N-(hydroxymethyl) acrylamide (NMA), and then β-CD-NMA was grafted on cellulose by means of the Fenton's reaction. The CD-grafted cellulose paper was characterized by ATR-FTIR analysis, SEM images, and mechanical properties.

Microextraction by packed sorbent followed by ultra high performance liquid chromatography for the fast extraction and determination of six antidepressants in urine.

The growing use of antidepressants in recent years has led to their increasing presence in forensic analyses. In this work, microextraction by packed sorbent followed by ultra-performance liquid chromatography with photodiode array detection provided a fast method for determining the antidepressants mirtazapine, venlafaxine, escitalopram, fluoxetine, fluvoxamine, and sertraline in human urine. The microextraction conditions (viz.

Gas-diffusion microextraction coupled with spectrophotometry for the determination of formaldehyde in cork agglomerates.

In this work, a simple methodology was developed for the extraction and determination of free formaldehyde content in cork agglomerate samples. For the first time, gas-diffusion microextraction was used for the extraction of volatile formaldehyde directly from samples, with simultaneous derivatization with acetylacetone (Hantzsch reaction). The absorbance of the coloured solution was read in a spectrophotometer at 412 nm.

Oxytetracycline recovery from aqueous media using computationally designed molecularly imprinted polymers.

Polymers for recovery/removal of the antimicrobial agent oxytetracycline (OTC) from aqueous media were developed with use of computational design and molecular imprinting. 2-Hydroxyethyl methacrylate, 2-acrylamide-2-methylpropane sulfonic acid (AMPS), and mixtures of the two were chosen according to their predicted affinity for OTC and evaluated as functional monomers in molecularly imprinted polymers and nonimprinted polymers. Two levels of AMPS were tested.

Response surface methodology for the optimization of dispersive liquid-liquid microextraction of chloropropanols in human plasma.

Chloropropanols are processing toxicants with a potential risk to human health due to the increased intake of processed foods. A rapid and efficient method for the determination of three chloropropanols in human plasma was developed using ultrasound-assisted dispersive liquid-liquid microextraction. The method involved derivatization and extraction in one step followed by gas chromatography with tandem mass spectrometry analysis.

Stimuli-responsive materials in analytical separation.

This review focuses on the fundamentals of stimuli-responsive materials and their applications to three common separation techniques, namely extraction, chromatography, and electrophoresis. Although still little investigated, materials that switch their affinity for the analyte on and off as a function of tiny changes in physical and biochemical variables offer relevant advantages for analyte extraction, concentration, and separation. Temperature and/or pH-responsive polymers in the form of chains or networks, which are dispersed in the sample as free entities or after being grafted onto beads (which may incorporate magnetic cores), enable quantitative capture and/or elution of the analyte under mild conditions and without needing organic solvents.

Applications of derivatization reactions to trace organic compounds during sample preparation based on pressurized liquid extraction.

Pressurized liquid extraction (PLE) is an exhaustive technique used for the extraction of analytes from solid samples. Temperature, pressure, solvent type and volume, and the addition of other reagents notably influence the efficiency of the extraction. The analytical applications of this technique can be improved by coupling with appropriate derivatization reactions.

Optimization of microwave-assisted extraction of analgesic and anti-inflammatory drugs from human plasma and urine using response surface experimental designs.

The performance of microwave-assisted extraction and HPLC with photodiode array detection method for determination of six analgesic and anti-inflammatory drugs from plasma and urine, is described, optimized, and validated. Several parameters affecting the extraction technique were optimized using experimental designs. A four-factor (temperature, phosphate buffer pH 4.

A rapid ultrasound-assisted dispersive liquid-liquid microextraction followed by ultra-performance liquid chromatography for the simultaneous determination of seven benzodiazepines in human plasma samples.

A simple and efficient ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) method has been developed for the determination of seven benzodiazepines (alprazolam, bromazepam, clonazepam, diazepam, lorazepam, lormetazepam and tetrazepam) in human plasma samples. Chloroform and methanol were used as extractant and disperser solvents, respectively. The influence of several variables (e.

Determination of chemotherapeutic agents in fish and shellfish by matrix solid-phase dispersion and liquid chromatography-tandem mass spectrometry.

Chemicals are widely used in aquaculture and one of the main recipients of these analytes is the aquatic environment. The aim of this work was to develop and validate a simple and sensitive method for the determination of multiclass chemotherapeutic agents in farmed fish and shellfish using matrix solid-phase dispersion and liquid chromatography-tandem mass spectrometry. Residues of azamethiphos, three avermectins, two carbamates, and two benzoylureas were extracted from samples using silica gel as clean-up adsorbent and 0.

Chromatographic determination of drugs of abuse in vitreous humor using solid-phase extraction.

A simple method is presented for the simultaneous determination of morphine, 6-acetylmorphine, codeine, cocaine, benzoylecgonine, cocaethylene, methadone and 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) in vitreous humor by high-performance liquid chromatography with photodiode array detector after solid-phase extraction with Oasis® HLB cartridges and dichloromethane as eluent. The chromatographic process was carried out using an XTerra® RP8 column (250 × 4.6 mm i.

To remove or not to remove? The challenge of extracting the template to make the cavities available in Molecularly Imprinted Polymers (MIPs).

Template removal is a critical step in the preparation of most molecularly imprinted polymers (MIPs). The polymer network itself and the affinity of the imprinted cavities for the template make its removal hard. If there are remaining template molecules in the MIPs, less cavities will be available for rebinding, which decreases efficiency.

A rapid analytical method based on microwave-assisted extraction for the determination of drugs of abuse in vitreous humor.

Robust and simple validated analytical methods are required in postmortem toxicology to confirm immunoassay screening analysis of drugs of abuse. In this work, microwave-assisted extraction (MAE) was evaluated as an alternative method for extraction of target compounds such as cocaine, benzoylecgonine, cocaethylene, morphine, codeine, 6-monoacetylmorphine, methadone, and 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine from vitreous humor. The MAE procedure parameters, namely, extraction temperature, time, and solvent volume, were optimized using a central composite design and applying desirability functions.

Combined solid-phase extraction and gas chromatography-mass spectrometry used for determination of chloropropanols in water.

A sensitive and rapid derivatization method for the simultaneous determination of 1,3-dichloro-2-propanol (1,3-DCP) and 3-chloropropane-1,2-diol (3-MCPD) in water samples has been developed. The aim was to research the optimal conditions of the derivatization process for two selected reagents. A central composite design was used to determine the influence of derivatization time, derivatization temperature and reagent volume.

Solid-phase micro-extraction procedure for the determination of 1,3-dichloro-2-propanol in water by on-fibre derivatisation with bis(trimethylsilyl)trifluoroacetamide.

The headspace solid-phase micro-extraction technique with on-fibre derivatisation followed by gas chromatography-tandem mass spectrometry has been evaluated for the analysis of 1,3-dichloro-2-propanol in water. An asymmetric factorial design has been performed to study the influence of five experimental factors: extraction time and temperature, derivatisation time and temperature and pH. The best extraction performance is achieved in the headspace mode, with 5 mL stirred water samples (pH 4) containing 1.

Determination of trace levels of aquaculture chemotherapeutants in seawater samples by SPME-GC-MS/MS.

A sensitive and efficient solid-phase microextraction (SPME) method for the determination of organophosphorous (OPPs) and pyrethroid pesticides (Pyrs) in aquaculture-seawater samples by using GC with MS/MS (GC-MS/MS) was developed. Dichlorvos and chlorpyrifos (OPPs); permethrin, alpha-cypermethrin and deltamethrin (Pyrs) were selected according to their use as chemotherapeutants in the aquaculture industry. Different parameters affecting extraction efficiency such as fibre coating, agitation, pH and extraction time profiles were investigated.

Microwave-assisted extraction and HPLC-DAD determination of drugs of abuse in human plasma.

A sample preparation procedure using microwave energy is proposed for the determination of morphine, 6-acetylmorphine, codeine, cocaine, cocaethylene, benzoylecgonine, methadone, and 2-ethylene-1,5-dimethyl-3,3-diphenylpyrrolidine in human plasma. A screening asymmetrical factorial design was used to identify the most suitable extraction conditions as regards solvent, temperature, and extraction time. The target drugs were quantified by high-performance liquid chromatography with diode-array detection.

Microwave assisted extraction of drugs of abuse from human urine.

Microwave assisted extraction (MAE) was used to extract drugs of abuse from urine samples for the simultaneous determination of morphine, codeine, 6-acetylmorphine (6AM), cocaine, cocaethylene, benzoylecgonine (BEG), methadone and 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) by high performance liquid chromatography with diode array detector (HPLC-DAD). The working wavelengths used were 285 nm for morphine, codeine and 6AM; 233 nm for cocaine, cocaethylene and BEG; and 292 nm for methadone and EDDP. The mobile phase was a gradient of acetonitrile and phosphate buffer at pH 6.