A sensitive determination of lead by hydride generation integrated with micro-sampling gas-liquid separator-FAAS after preconcentration by NiFeO nanoparticles.

In the present study, dispersive solid phase extraction - hydride generation integrated with micro-sampling gas-liquid separator - flame atomic absorption spectrometry was proposed to determine lead in lake water samples taken in the Horseshoe Island, Antarctica. In scope of this study, microwave assisted NiFeO nanoparticles were synthesized, and the characterization of nanoparticles were carried out by FT-IR, XRD and SEM. All influential parameters of dispersive solid phase extraction and hydride generation were optimized to enhance signal intensity belonging to the analyte.

Combination of quadruple isotope dilution strategy and dispersive solid phase extraction method for accurate quantification of selected steroid hormones.

Steroid hormones are essential for the regulation of various vital body functions. Therefore, the determination of steroid hormones in biological fluids is a significant issue to find out the mechanism of steroid hormones related to disorders. In this study, FeO/reduced graphene oxide (FeO/rGO) nanocomposite based dispersive solid phase extraction (DSPE) was coupled with liquid chromatography - quadruple isotope dilution - triple quadrupole mass spectrometry (LC-ID-MS/MS) for the accurate and precise determination of aldosterone, testosterone, 17-hydroxyprogesterone and estrone in serum samples.

Top-down predators shape soil bacterial community composition while bottom-up nutrients drive bacterial abundance.

Although the top-down and bottom-up concept in microbial food-webs has been a primary interest in ecology, less is still known about it in soil ecosystems. Protists are the primary top-down predators of bacterial communities, altering their compositions, while the bottom-up resources are the primary factors limiting bacterial growth. Here, we hypothesized that the top-down predators modulate soil bacterial community composition, while the bottom-up nutrients control the bacterial growth and population.

Simultaneous determination of nineteen azo dyes in water samples by gas chromatography-mass spectrometry after FeO@COF based dispersive solid phase extraction.

This study was performed for the determination of nineteen azo dyes at trace levels in stream water sample by gas chromatography-mass spectrometry (GC-MS). The selected analytes were preconcentrated with the help of dispersive solid phase extraction (DSPE). FeO magnetic nanoparticle was modified with covalent organic framework (COF) and the synthesized FeO@COF nanocomposite was used as adsorbent for the separation of the analytes from aqueous solution.

Development of dispersive solid phase extraction method for the preconcentration of parathion ethyl as a simulant of nerve agent sarin from soil, plant and water samples prior to GC-MS determination.

In the presented study, an efficient and fast analytical method was developed for the determination of parathion ethyl as sarin simulant by gas chromatography-mass spectrometry (GC-MS). Dispersive solid phase extraction (DSPE) was performed to concentrate parathion ethyl from soil, plant and water samples. Reduced graphene oxide-iron (II, III) oxide (rGO-FeO) nanocomposite was used as an adsorbent to collect the target analyte from the aqueous sample solutions.

Determination of capsaicin at trace levels in different food, biological and environmental samples by quadruple isotope dilution-gas chromatography mass spectrometry after its preconcentration.

Despite the therapeutic properties of capsaicin for some diseases, it shows some side effects for human health. The goal of this study was to develop a precise and accurate analytical strategy for the trace determination of capsaicin in different food, biological and environmental samples including pepper, saliva and wastewater by gas chromatography-mass spectrometry (GC-MS) after spraying-based fine droplet formation-liquid phase microextraction (SFDF-LPME) and quadruple isotope dilution (ID) method. Acetic anhydride was used as derivatizing agent, and the extraction method was used to enrich the analyte derivative to reach low detection limits.

Determination of phenytoin at trace levels in domestic wastewater and synthetic urine samples by gas chromatography-mass spectrometry after its preconcentration by simple liquid-phase microextraction.

This work presents a sensitive and accurate analytical method for the determination of phenytoin at trace levels in domestic wastewater and synthetic urine samples by gas chromatography-mass spectrometry (GC-MS) after the metal sieve-linked double syringe liquid-phase microextraction (MSLDS-LPME) method. A metal sieve was produced in our laboratory in order to disperse water-immiscible extraction solvents into aqueous media. Univariate optimization studies for the selection of proper extraction solvent, extraction solvent volume, mixing cycle, and initial sample volume were carried out.

An accurate and sensitive determination of selected pesticides in mixed fruit juice samples using the combination of a simple and efficient microextraction method and GC-MS with a matrix matching calibration strategy.

Pesticides have been used on several fruits, vegetables and cereals to control harmful organisms in order to increase the quality of products; however, these substances cause serious health effects. Therefore, an accurate and sensitive analytical method should be developed for the determination of pesticides to evaluate their toxicity. In this study, an efficient microextraction strategy was applied to preconcentrate eight different selected pesticides from mixed fruit juice samples prior to gas chromatography-mass spectrometry detection.

Determination of copper ion at trace levels in apple tea samples by simultaneous complexation and spray assisted microextraction method prior to detection by flame atomic absorption spectrophotometry.

In the present study, a green and sensitive analytical method for the determination of copper ion at trace levels in apple tea samples was developed. Simultaneous complexation/extraction of the analyte were achieved by spraying-based fine droplet formation liquid-phase microextraction (SFDF-LPME). Copper ion was complexed with a Schiff base chelating agent called as N,N'-Bis(salicylidene)-1,2-phenylenediamine (BSP).

Determination of copper in rose tea samples using flame atomic absorption spectrometry after emulsification liquid-liquid microextraction.

Rose tea infusion has gained popularity worldwide due to its health benefits. However, it is known that tea plants can be contaminated with heavy metals including copper. Hence, an accurate and applicable analytical method namely emulsification liquid-liquid microextraction based deep eutectic solvent - flame atomic absorption spectrometry (ELLME-DES-FAAS) was proposed to determine copper at trace levels in rose tea samples.

Biogenic synthesis of novel nanomaterials and their applications.

Despite the many benefits derived from the unique features and practicality of nanoparticles, the release of their toxic by-products or products from the synthesis stage into the environment could negatively impact natural resources and organisms. The physical and chemical methods for nanoparticle synthesis involve high energy consumption and the use of hazardous chemicals, respectively, going against the principles of green chemistry. Biological methods of synthesis that rely on extracts from a broad range of natural plants, and microorganisms, such as fungi, bacteria, algae, and yeast, have emerged as viable alternatives to the physical and chemical methods.

Deep eutectic solvents for the determination of endocrine disrupting chemicals.

The harmful effects of endocrine disrupting chemicals (EDCs) to humans and other organisms in the environment have been well established over the years, and more studies are ongoing to classify other chemicals that have the potential to alter or disrupt the regular function of the endocrine system. In addition to toxicological studies, analytical detection systems are progressively being improved to facilitate accurate determination of EDCs in biological, environmental and food samples. Recent microextraction methods have focused on the use of green chemicals that are safe for analytical applications, and present very low or no toxicity upon disposal.

Dose-Dependent Enuresis in Methylphenidate Use.

Objectives: Attention deficit hyperactivity disorder (ADHD) is one of the most common neurodevelopmental disorders of childhood. Although enuresis is a very common disorder in child diagnosed with ADHD, it may also develop because of methylphenidate.

Methods: Authors report here on a child case of ADHD that developed a probable enuresis related to methylphenidate.

Combination of high performance liquid chromatography and flame atomic absorption spectrophotometry using a novel nebulizer interface supported T shaped slotted quartz tube for the determination of Vitamin B12.

A novel nebulizer interface (NI) was proposed to combine high performance liquid chromatography (HPLC) and flame atomic absorption spectrophotometer (FAAS). A glass concentric nebulizer was linked to T-shaped slotted quartz tube (T-SQT) using a tubing to transfer the liquid solution eluted from the chromatographic system into the atomization region of FAAS system. T-SQT was also used to intensify the interaction of atoms with the hollow cathode lamp light.

A simple and efficient derivatization strategy combined with switchable solvent liquid-liquid microextraction hydroxychloroquine methyl acetate-d -based quadruple isotope dilution gas chromatography mass spectrometry for the determination of hydroxychloroquine sulfate in biological fluids.

Rationale: A derivatization switchable solvent liquid-liquid microextraction quadruple isotope dilution gas chromatography mass spectrometry (D-SS-LLME-ID -GC/MS) method is presented for the determination of hydroxychloroquine sulfate in human biofluids.

Methods: While mixing type/period and concentration of NaOH were optimized via a univariate optimization approach, a multivariate optimization approach was used to determine optimum values for relatively more important parameters such as volumes of derivatization agent (acetic anhydride), NaOH and switchable solvent.

Results: Under the optimum experimental conditions, limit of detection and limit of quantification were calculated as 0.

Accurate determination of amino acids by quadruple isotope dilution-reverse phase liquid Chromatography-Tandem mass spectrometry after derivatization with 2-Naphthoyl chloride.

The determination of amino acids in biological samples is central to the diagnosis of inherited metabolic disorders and also gives significant information about the metabolisms in the cells and living body. The development of analytical method for reliable quantification of amino acids in biological samples is still challenging because of the polar nature of amino acids and complex nature of biological samples causing a high degree of interferences during analysis. In the present study, a pre-column derivatization method using 2-naphtoyl chloride combined with liquid chromatography-tandem mass spectrometry method was developed for the determination of 17 amino acids in human serum and urine matrices.

One step derivatization and dispersive liquid-liquid microextraction of hydroxychloroquine sulfate for its sensitive and accurate determination using GC-MS.

In the present study, a novel analytical method for the determination of hydroxychloroquine sulfate in human serum and urine samples was established. One step derivatization and dispersive liquid-liquid microextraction (DLLME) was developed for quantitative determination of hydroxychloroquine sulfate in aqueous samples. Hydroxychloroquine sulfate was first hydrolyzed and converted to its benzoate derivative by adding benzoyl chloride in chloroform which also served as extraction solvent.

Determination of selenite and selenomethionine in kefir grains by reversed-phase high-performance liquid chromatography-inductively coupled plasma-optical emission spectrometry.

A new and efficient reversed-phase high-performance liquid chromatography-inductively coupled plasma-optical emission spectrometry method was developed for the simultaneous separation and determination of SeO and seleno-dl-methionine in kefir grains. For the system, limits of detection and quantitation values for SeO and seleno-dl-methionine were calculated as 0.52/1.

Quadruple isotope dilution gas chromatography-mass spectrometry after simultaneous derivatization and spraying based fine droplet formation liquid phase microextraction method for the accurate and sensitive quantification of chloroquine phosphate in human serum, urine and saliva samples at trace levels.

This study presents an accurate and precise analytical strategy for the determination of chloroquine phosphate at trace levels in human body fluids (urine, serum, and saliva). Simultaneous derivatization-spraying based fine droplet formation-liquid phase microextraction (SD-SFDF-LPME) method was used to derivatize and preconcentrate the analyte prior to gas chromatography-mass spectrometry (GC-MS) measurements. Acetic anhydride was employed as derivatizing agent in this study.

A Novel Hydrogen Fluoride Assisted-Glass Surface Etching Based Liquid Phase Microextraction for the Determination of 4-n-Nonylphenol in Water by Gas Chromatography-Mass Spectrometry with Matrix Matching Strategy.

A novel extraction method named hydrogen fluoride assisted-glass surface etching based liquid phase microextraction (HF-GSE-LPME) was proposed to determine 4-n-nonylphenol at trace levels by gas chromatography-mass spectrometry (GC-MS). After the evaluation of system analytical performance for the HF-GSE-LPME-GC-MS system, limit of detection (LOD) and limit of quantification (LOQ) values were calculated as 7.1 and 23.

Nanoparticles Based Extraction Strategies for Accurate and Sensitive Determination of Different Pesticides.

Sample preparation methods have become indispensable steps in analytical measurements not only to lower the detection limit but also to eliminate the matrix effect although more sophisticated instruments are being commonly used in routine analyses. Solid phase extraction (SPE) is one of the main extraction/preconcentration methods used to extract and purify target analytes along with simple and rapid procedures but some limitations have led to seek for an easy, sensitive and fast extraction methods with analyte-selective sorbents. Nanoparticles with different modifications have been used as spotlight to enhance extraction efficiency of target pesticides from complicated matrices.

Accurate and sensitive determination of hydroxychloroquine sulfate used on COVID-19 patients in human urine, serum and saliva samples by GC-MS.

A rapid, accurate, and sensitive analytical method, ultrasonication-assisted spraying based fine droplet formation-liquid phase microextraction-gas chromatography-mass spectrometry (UA-SFDF-LPME-GC-MS), was proposed for the determination of trace amounts of hydroxychloroquine sulfate in human serum, urine, and saliva samples. To determine the best extraction strategy, several liquid and solid phase extraction methods were investigated for their efficiencies in isolation and preconcentration of hydroxychloroquine sulfate from biological matrices. The UA-SFDF-LPME method was determined to be the best extraction method as it was operationally simple and provided accurate results.

Development of an easy and rapid analytical method for the extraction and preconcentration of chloroquine phosphate from human biofluids prior to GC-MS analysis.

A vortex assisted spraying based fine droplet formation liquid phase microextraction (VA-SFDF-LPME) method was developed to determine chloroquine phosphate at trace levels in human serum, urine and saliva samples by gas chromatography-mass spectrometry (GC-MS) with single quadrupole mass analyzer. In the first part, several liquid phase microextraction (LPME) and magnetic solid phase extraction (MSPE) methods were compared to each other in order to observe their extraction ability for the analyte. VA-SFDF-LPME method was selected as an efficient and easy extraction method due to its higher extraction efficiency.