Application of porous membrane protected micro-solid-phase-extraction combined with gas chromatography–mass spectrometry for the determination of estrogens in ovarian cyst fluid samples

Review of the Use of Liquid Chromatography-Tandem Mass Spectrometry in Clinical Laboratories: Part II-Operations

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is increasingly utilized in clinical laboratories because it has advantages in terms of specificity and sensitivity over other analytical technologies. These advantages come with additional responsibilities and challenges given that many assays and platforms are not provided to laboratories as a single kit or device. The skills, staff, and assays used in LC-MS/MS are internally developed by the laboratory, with relatively few exceptions. Hence, a laboratory that deploys LC-MS/MS assays must be conscientious of the practices and procedures adopted to overcome the challenges associated with the technology. This review discusses the post-development landscape of LC-MS/MS assays, including validation, quality assurance, operations, and troubleshooting. The content knowledge of LC-MS/MS users is quite broad and deep and spans multiple scientific fields, including biology, clinical chemistry, chromatography, engineering, and MS. However, there are no formal academic programs or specific literature to train laboratory staff on the fundamentals of LC-MS/MS beyond the reports on method development. Therefore, depending on their experience level, some readers may be familiar with aspects of the laboratory practices described herein, while others may be not. This review endeavors to assemble aspects of LC-MS/MS operations in the clinical laboratory to provide a framework for the thoughtful development and execution of LC-MS/MS applications.

Trends in Innovations and Recent Advances in Membrane Protected Extraction Techniques for Organics in Complex Samples

Membrane protected extraction is an ongoing innovation for isolation and pre-concentration of analytes from complex samples. The extraction process, clean-up and pre-concentration of analytes occur in a single step. The inclusion of solid sorbents such as molecularly imprinted polymers (MIPs) after membrane extraction ensures that selective double extraction occurs in a single step. The first step involves selective extraction using the membrane and diffused analytes are trapped on the solid sorbent enclosed in the membrane. No further clean-up is required even for very dirty samples like plant extracts and wastewaters samples. Sample clean-up occurs during extraction in the first process and not as additional step since matrix components are prevented from trapping on the sorbent. This can be referred to as prevention is better than cure approach. In this work, the analytical methods that employed membrane protected extraction for various organics such as pesticides, polycyclic aromatic hydrocarbons, and pharmaceuticals are reviewed. The designs of these analytical methods, their applications, advantages and drawbacks are discussed in this review. Literature suggests that the introduction of solid sorbents in membrane creates the much-needed synergy in selectivity. Previous reviews focused on membrane combinations with MIPs while discussing micro-solid-phase extraction. The scope of this review was broadened to include other sample preparation aspects such as membrane protected stir bar solvent extraction and membrane protected solid-phase microextraction. In addition, novel sample preparation methods for solid samples which include Soxhlet membrane protected molecular imprinted solid phase extraction and membrane protected ultra sound assisted extracted are discussed.

Sodium dodecyl sulfate-multi-walled carbon nanotubes-coated-membrane solid phase extraction of glucocorticoids in aqueous matrices

A membrane-based solid phase extraction (SPE)-ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed for the determination of nine glucocorticoids in water. This new hybrid SPE approach involved the deposition of sodium dodecyl sulfate (SDS)-multi-walled carbon nanotubes (MWCNTs) on a piece of polypropylene membrane that served as the extraction device. Hitherto, such a sample preparation procedure has not been applied to the analysis of water contaminants before. The use of the surfactant helped to disperse the MWCNTs effectively so that they were coated uniformly onto the polypropylene membrane. This increased the overall extraction efficiency of the procedure. Characterisation of the SDS-MWCNTs material was performed using transmission electron microscopy and scanning electron microscopy. The membrane device did not require a pre-conditioning step. The most favourable extraction parameters such as type of surfactant, percentage of surfactant, type of desorption solvent, stirring rate, desorption time, extraction time, temperature, salting-out effect, pH and diameter of MWCNTs were obtained. The method showed linearity ranges from 0.2 to 100 ng mL^-1 for hydrocortisone, dexamethasone, cortisone acetate and beclomethasone dipropionate, and 0.5-100 ng mL^-1 for the rest of the analytes. Limits of detection ranging from 0.019 to 0.098 ng mL^-1, and limits of quantification ranging from 0.065 to 0.326 ng mL^-1, were obtained for the analytes. The intra-day repeatability was between 1.77 and 3.56% while the inter-day reproducibility was between 2.69 and 9.53%, respectively. The method was used to analyse glucocorticoids as contaminants in the canal water samples.

Graphene and zeolite as adsorbents in bar-micro-solid phase extraction of pharmaceutical compounds of diverse polarities

A bar micro-solid phase (bar μ-SPE) extraction method using either graphene or zeolite or their mixtures as an adsorbent, coupled with high-performance liquid chromatography (using a C1 column) was developed for the simultaneous determination of pharmaceutical compounds (metformin (MET), buformin (BUF), phenformin (PHEN) and propranolol (PROP)) of diverse polarity (log P from −1.82 to 3.10). Parameters influencing the extraction, such as conditioning solvents, pH of the sample, sample volume, amount of adsorbent, stirring rate, time of extraction, type and volume of desorption solvent and time of desorption were investigated. Under the optimized conditions, the extraction method using graphene (extraction efficiency, % EE, ∼6–15%) resulted in the least amount of extracted drugs. However, the use of zeolite and zeolite/graphene mixtures improves the % EE significantly, i.e. 30% for PHEN and 42% for PROP using zeolite; 22% for MET and 18% for BUF using the adsorbent mixture. Under similar conditions, enrichment factors for these drugs range from 11–15. The validated method was performed for the determination of the drugs that were spiked to urine samples. Good recoveries ranging from 72.8 to 116% were achieved.

A bar micro-solid phase (bar μ-SPE) extraction method using either graphene or zeolite or their mixtures as an adsorbent, coupled with high-performance liquid chromatography was developed for the determination of pharmaceutical compounds of diverse polarity.

Advances in organic-inorganic hybrid sorbents for the extraction of organic and inorganic pollutants in different types of food and environmental samples

The efficiency of the extraction and removal of pollutants from food and the environment has been an important issue in analytical science. By incorporating inorganic species into an organic matrix, a new material known as an organic-inorganic hybrid material is formed. As it possesses high selectivity, permeability, and mechanical and chemical stabilities, organic-inorganic hybrid materials constitute an emerging research field and have become popular to serve as sorbents in various separaton science methods. Here, we review recent significant advances in analytical solid-phase extraction employing organic-inorganic composite/nanocomposite sorbents for the extraction of organic and inorganic pollutants from various types of food and environmental matrices. The physicochemical characteristics, extraction properties, and analytical performances of sorbents are discussed; including morphology and surface characteristics, types of functional groups, interaction mechanism, selectivity and sensitivity, accuracy, and regeneration abilities. Organic-inorganic hybrid sorbents combined with extraction techniques are highly promising for sample preparation of various food and environmental matrixes with analytes at trace levels.

Porous membrane protected micro-solid-phase extraction: A review of features, advancements and applications

Membrane protected micro-solid-phase extraction (μ-SPE) was introduced in 2006 as an alternative to multistep SPE. μ-SPE is based on packing of very small amount of sorbent inside the porous membrane sheet whose edges are heat sealed to fabricate a μ-SPE device. This device performs clean up, extraction, and pre-concentration in a single step. It suits best for extraction of complex samples as sorbent is effectively protected inside the membrane and extraneous matter cannot adsorb over it. This review summarizes most important aspects of μ-SPE including basic principles, extraction procedure, different formats, sorbents employed and affecting parameters. The article also provides a brief account on modified μ-SPE procedures where μ-SPE was either combined with other techniques or some major changes were introduced in original procedure. Finally, the applications of μ-SPE in environmental, food and biological analysis are described. At the end, advantages and pitfalls of μ-SPE are critically appraised.

Application of surfactant-templated ordered mesoporous material as sorbent in micro-solid phase extraction followed by liquid chromatography-triple quadrupole mass spectrometry for determination of perfluorinated carboxylic acids in aqueous media

In the present study, micro-solid phase extraction (µ-SPE) followed by liquid chromatography-triple tandem mass spectrometery (LC-MS/MS) was developed for the determination of perfluorocarboxylic acids (PFCAs) at trace levels in water samples. The µ-SPE device comprised of a porous polypropylene membrane bag containing 5mg sorbent. The membrane bag acted as a clean-up filter and prevented matrix compounds from interfering with the extraction process. Analysis was carried out by LC-MS/MS in negative electrospray ionization mode. MS/MS parameters were optimized for multiple reaction monitoring. Calcined and non-calcined MCM-41, as silica-ordered mesoporous materials, were used as sorbents in µ-SPE for the extraction of five PFCAs-perfluoropentanoic acid (PFPA), perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA)-from aqueous media. The performances of these two sorbents were compared with other sorbents such as octadecylsilane (C18) modified silica, HayeSep-A, HayeSep-B, and Porapak-R. It was found that non-calcined MCM-41 showed better extraction performance for the analytes considered. Parameters influencing extraction efficiency, such as desorption time, extraction time, desorption solvent, and salt concentration, were investigated. The effect of the matrix on MS signals (suppression or enhancement) was also evaluated. Only minor effects on ionization efficiencies were observed. The developed method proved to be convenient and offered good sensitivity and reproducibility. The limits of detection ranged from 0.02 to 0.08ng L(-1), with a relative standard deviations between 1.9 and 10.5. It was successfully applied to the extraction of PFCAs in river and rain water samples. As expected from the ubiquitous nature of PFCAs, contamination at low levels was detected for some analytes in the samples (with the highest concentration recorded for PFOA). Satisfactory relative recoveries ranging between 64% and 127% at spiking levels of 10ng L(-1) of each analyte were obtained.

Metal–organic framework MIL-101(Cr) as a sorbent of porous membrane-protected micro-solid-phase extraction for the analysis of six phthalate esters from drinking water: a combination of experimental and computational study

An attractive MIL-101(Cr) material was synthesized and applied as a sorbent in μ-SPE device for the pre-concentration of PAEs in drinking water for the first time.

Preparation of an allyloxy-cucurbit[6]uril-modified polymer monolithic column for microextraction of estrogens in cosmetics

An allyloxy-cucurbit[6]uril modified poly(butyl methacrylate-co-ethylene dimethacrylate) monolithic column was prepared and used for the microextraction of estrogens in cosmetics coupled with HPLC-DAD.

A Novel Extraction-Cleanup Method for Determination of Trace PPCPs in Water Samples

In this contribution, a simple and sensitive extraction-cleanup method which was termed MAE-μ-SPE, was developed for the analysis of pharmaceutical and personal care products (PPCPs) in environmental water samples. The PPCPs included bisphenol A (BPA), diethyl phthalate (DEP), dibutyl phthalate (DBP), di (2-ethylhexyl) phthalate (DEHP), tetracycline (TC), deoxytetracycline (DC), oxytetracycline (OTC) and chloroteracycline (CTC). In this method, the PPCPs in the samples were extracted by microwave-assisted extraction (MAE) following adsorbed by copper (II) isonicotinate in micro-solid phase extraction (μ-SPE) device. The PPCPs were determined by high performance liquid chromatography with ultra-violet detector (HPLC-UV). The procedure of the MAE-μ-SPE was optimized in extraction temperature, extraction time, desorption time and desorption solvent. Analytical performances, such as limits of detection (in the range of 2.0-8.5 μg/L), quantification (in the range of 6.6-28.0 μg/L), and repeatability of the over-all procedure (less than 13%) were established. DEP, DBP, DEHP and TC studied in water samples were ranged from 18.2-68.8 μg L-1, while BPA, OTC, CTC and DC were found all below the detection limit in these samples.

Tea bag filter paper as a novel protective membrane for micro-solid phase extraction of butachlor in aqueous samples

An innovative, cost-effective, simple, and environmental friendly tea bag filter paper protected micro-solid phase extraction (μ-SPE) technique was developed for the first time with the aim to miniaturize and minimize the use of organic solvents for the extraction and determination of butachlor in aqueous samples. The μ-SPE device was produced by packing 3.0 mg of an easily synthesized new sorbent, hydroxyl-functionalized polypyrrole (OH-PPY), inside a small tea bag filter paper sachet (1.0 cm × 0.5 cm) that served as a protective envelope. Both the extraction and desorption procedures were facilitated by sonication. Due to the high porosity and the fast water absorption of the tea bag filter paper, the analyte could easily diffuse through and enhance the interaction with the sorbent. Under the optimized conditions for the GC-ECD and the μ-SPE, the limit of detection (S/N ≥ 3) was 2.0 μg L(-1) while the limit of quantitation (S/N ≥ 10) was 10.0 μg L(-1). The recoveries of the butachlor spiked at 0.050, 0.10, and 0.50 μg mL(-1) ranged from 77.9 ± 3.0 to 112.5 ± 2.9%. The proposed method was successfully applied for the determination of butachlor in water samples from paddy cultivation sites. The levels found were from non-detectable to 24.71 ± 0.37 μg L(-1).

Determination of hyperoside and isoquercitrin in rat plasma by membrane-protected micro-solid-phase extraction with high-performance liquid chromatography

A novel method, micro-solid-phase extraction based on membrane-protected molecularly imprinted polymer, was developed to extract hyperoside and isoquercitrin in rat plasma. Synthesized hyperoside MIPs were packed in a porous polyether sulfone membrane envelope to perform extraction. The parameters sorbent materials, membrane types, extraction time and desorption conditions were optimized for micro-solid-phase extraction. Under the optimal conditions, correlation coefficients, 0.998 and 0.999, were obtained for hyperoside and isoquercitrin, respectively, with the linear range between 1 and 120 μg/mL. The absolute extraction recoveries from 84.5 to 89.3% were found. The method detection limits of hyperoside and isoquercitrin were 0.24 and 0.22 μg/mL, respectively. Compared with traditional methods, solid-phase extraction, liquid-liquid extraction and protein precipitation, the developed method was simple, highly efficient for extraction, environmentally friendly, and particularly suitable for complex biological samples.