The freely dissolved concentration (Cfree) of hydrophobic organic chemicals in sediments and soils is considered the driver behind chemical bioavailability and, ultimately, toxic effects in benthic organisms. Therefore, quantifying Cfree, although challenging, is critical when assessing risks of contamination in field and spiked sediments and soils (e.g., when judging remediation necessity or interpreting results of toxicity assays performed for chemical safety assessments). Here, we provide a state-of-the-art passive sampling protocol for determining Cfree in sediment and soil samples. It represents an international consensus procedure, developed during a recent interlaboratory comparison study. The protocol describes the selection and preconditioning of the passive sampling polymer, critical incubation system component dimensions, equilibration and equilibrium condition confirmation, quantitative sampler extraction, quality assurance/control issues and final calculations of Cfree. The full procedure requires several weeks (depending on the sampler used) because of prolonged equilibration times. However, hands-on time, excluding chemical analysis, is approximately 3 d for a set of about 15 replicated samples.

• MeSH
• Geologic Sediments analysis   MeSH
• Hydrophobic and Hydrophilic Interactions MeSH
• Soil Pollutants analysis   MeSH
• Solid Phase Microextraction methods   MeSH
• Soil chemistry   MeSH
• Environmental Pollution MeSH
• Publication type
• Journal Article MeSH
• Evaluation Study MeSH
• Research Support, Non-U.S. Gov't MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH

Carbamazepine is an antiepileptic drug with a narrow therapeutic index, which requires an efficient method for blood level monitoring. Finger-prick dried blood spot (DBS) collection is an alternative microsampling technique, which is less invasive than conventional venipuncture. Paper-based molecularly imprinted-interpenetrating polymer networks (MI-IPN) were developed as blood collection devices, which allowed for selective on-spot microextraction of carbamazepine from DBS. A hybrid of homogeneous polystyrene and silica gel polymer was synthesized and coated on a Whatman® Grade 1 filter paper. Proteins and other interferences in the blood samples were eliminated by using the MI-IPN collection devices, and the resulting DBS extracts were suitable for direct injection into the capillary electrophoretic instrument. The lower limit of quantitation of 4 μg/mL in capillary blood was achieved by the sweeping-micellar electrokinetic chromatography method using a KCl-containing matrix, which was sufficient for the therapeutic drug monitoring purposes. Method accuracies were in the range of 88.4 ± 4.5% to 94.5 ± 2.7% with RSD values ≤ 5.1%. The developed paper-based MI-IPN provided superior extraction efficiencies (92.2 ± 2.5%) in comparison with commercially available DBS collection cards, i.e., Whatman® 903 protein saver card (59.8 ± 2.8%) and GenCollect™ 2.0 card (47.2 ± 1.4%). The paper-based MI-IPN devices for DBS collection and on-spot extraction were characterized by simple fabrication, low costs, disposability, and reduction in sample preparation steps, and their further developments might open new perspectives in clinical applications, such as in therapeutic drug monitoring. Graphical abstract.

• MeSH
• Anticonvulsants blood   isolation & purification   MeSH
• Electrophoresis, Capillary methods   MeSH
• Carbamazepine blood   isolation & purification   MeSH
• Humans MeSH
• Solid Phase Microextraction methods   MeSH
• Molecularly Imprinted Polymers chemistry   MeSH
• Drug Monitoring MeSH
• Blood Specimen Collection methods   MeSH
• Paper MeSH
• Tandem Mass Spectrometry MeSH
• Dried Blood Spot Testing methods   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH

Solid-phase microextraction (SPME) is an alternative method to dialysis and ultrafiltration for the determination of plasma protein binding (PPB) of drugs. It is particularly advantageous for complicated analytes where standard methods are not applicable. Di-2-pyridylketone 4-cyclohexyl-4-methyl-3-thiosemicarbazone (DpC) is a lead compound of novel thiosemicarbazone anti-cancer drugs, which entered clinical trials in 2016. However, this agent exhibited non-specific binding on filtration membranes and had intrinsic chelation activity, which precluded standard PPB methods. In this study, using a simple and fast procedure, we prepared novel SPME fibers for extraction of DpC based on a metal-free, silicon string support, covered with C18 sorbent. Reproducibility of the preparation process was demonstrated by the percent relative standard deviation (RSD) of ≤ 9.2% of the amount of DpC extracted from PBS by several independently prepared fibers. The SPME procedure was optimized by evaluating extraction and desorption time profiles. Suitability of the optimized protocol was verified by examining reproducibility, linearity, and recovery of DpC extracted from PBS or plasma. All samples extracted by SPME were analyzed using an optimized and validated UHPLC-MS/MS method. The developed procedure was applied to the in vitro determination of PPB of DpC at two clinically relevant concentrations (500 and 1000 ng/mL). These studies showed that DpC is highly bound to plasma proteins (PPB ≥ 88%) and this did not differ significantly between both concentrations tested. This investigation provides novel data in the applicability of SPME for the determination of PPB of chelators, as well as useful information for the clinical development of DpC. Graphical abstract.

• MeSH
• Adsorption MeSH
• Equipment Design MeSH
• Silicon chemistry   MeSH
• Blood Proteins metabolism   MeSH
• Rats MeSH
• Solid Phase Microextraction instrumentation   methods   MeSH
• Antineoplastic Agents metabolism   MeSH
• Pyridines metabolism   MeSH
• Cattle MeSH
• Tandem Mass Spectrometry methods   MeSH
• Thiosemicarbazones metabolism   MeSH
• Protein Binding MeSH
• Chromatography, High Pressure Liquid methods   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Cattle MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

RATIONALE: The major objective of this exploratory study was to implement selected ion flow tube mass spectrometry, SIFT-MS, as a method for the on-line quantification of the volatile organic compounds, VOCs, in the headspace of the ground roasted coffee. METHODS: The optimal precursor ions and characteristic analyte ions were selected for real-time SIFT-MS quantification of those VOCs that are the most abundant in the headspace or known to contribute to aroma. NO+ reagent ion reactions were exploited for most of the VOC analyses. VOC identifications were confirmed using gas chromatography/mass spectrometry, GC/MS, coupled with solid-phase microextraction, SPME. RESULTS: Thirty-one VOCs were quantified, including several alcohols, aldehydes, ketones, carboxylic acids, esters and some heterocyclic compounds. Variations in the concentrations of each VOC in the seven regional coffees were typically less than a factor of 2, yet concentrations patterns characteristic of the different regional coffees were revealed by heat map and principal component analyses. The coefficient of variation in the concentrations across the seven coffees was typically below 24% except for furfural, furan, methylfuran and guaiacol. CONCLUSIONS: The SIFT-MS analytical method can be used to quantify in real time the most important odoriferous VOCs in ground coffee headspace to sufficient precision to reveal some differences in concentration patterns for coffee produced in different countries.

• MeSH
• Aldehydes analysis   MeSH
• Alcohols analysis   MeSH
• Principal Component Analysis MeSH
• Food Analysis methods   MeSH
• Coffea chemistry   MeSH
• Mass Spectrometry methods   MeSH
• Coffee chemistry   MeSH
• Ketones analysis   MeSH
• Food Handling MeSH
• Solid Phase Microextraction methods   MeSH
• Gas Chromatography-Mass Spectrometry methods   MeSH
• Volatile Organic Compounds analysis   chemistry   MeSH
• Publication type
• Journal Article MeSH

AIM: Micro-SPE in pipette tips (μ-SPE-PT) with particle sorbent has never been used in small-molecule drug analysis. Methodology & results: μ-SPE-PT was used for the extraction of statins from biological materials followed by UHPLC-MS/MS. The commercial and homemade μ-SPE-PT tips filled with particle sorbent were compared. While the homemade tips enabled direct serum sample loading into the sorbent, protein precipitation (PP) had to be implemented before μ-SPE-PT procedure using commercial tips. Three μ-SPE-PT methods were developed and validated: method A: μ-SPE-PT with homemade tips; method B: PP + μ-SPE-PT with homemade tips; and method C: PP + μ-SPE-PT with commercial tips. Method A enabled a simple high-throughput approach (48 samples in 90 min) compared with methods B and C that required three-times longer time. However, PP increased the recoveries of protein-bound analytes and extracts purity in methods B and C. The matrix effects without internal standards correction for method C were significantly higher than those for the methods A and B. CONCLUSION: Compared with commercial tips, homemade tips filled with particles were found to be more suitable for drug analysis. Commercial tips tested in this study were found challenging but the conditions under which they could be applicable were also defined.

• MeSH
• Equipment Design MeSH
• Pharmaceutical Preparations blood   MeSH
• Humans MeSH
• Limit of Detection MeSH
• Solid Phase Microextraction instrumentation   methods   MeSH
• Tandem Mass Spectrometry methods   MeSH
• Chromatography, High Pressure Liquid methods   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Validation Study MeSH

Instrumental human scent analysis is undoubtedly desirable for many forensic as well medical applications. Most of the previous human scent studies were focused on volatile organic compounds (VOCs) which were analysed by head space solid phase micro-extraction gas chromatography/mass spectrometry (HS-SPME-GC/MS). This method is, however, significantly less sensitive to "heavier" less volatile compounds emitted from the human skin. These less volatile organic scent molecules probably create the basis of the individual human scent signature, and therefore, our attention is focused mainly on these "heavier" compounds. The human scent was adsorbed onto purified glass beads and samples were prepared as hexane solutions obtained by extraction from the sampled glass beads. To resolve a lot of very similar molecules, the comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometer (GCxGC-TOFMS) was used to analyse the hexane scent solutions. Using this technique, more than 137 less volatile molecules including organic fatty acids, ketones, aldehydes, simple esters, alcohols, and especially various fatty acid esters with different carbon chains were identified. A considerable number of these molecules were identified in the scent samples for the first time.

• MeSH
• Adsorption MeSH
• Humans MeSH
• Solid Phase Microextraction methods   MeSH
• Skin Cream chemistry   MeSH
• Gas Chromatography-Mass Spectrometry instrumentation   methods   MeSH
• Volatile Organic Compounds chemistry   isolation & purification   MeSH
• Check Tag
• Humans MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Evaluation Study MeSH

BACKGROUND: Statins are the microsomal 3-hydroxy-3methylglutaryl-coenzyme A reductase inhibitors used for the treatment of hypercholesterolemia. Some recent studies revealed also the extra-lipid effects and anticancer activities. Due to the wide incidence of cancer diseases, the number of studies dealing with anticancer statin activities has grown in recent years. Development of one universal multistatin method will be a very convenient way of providing practical and economical multiple statin analysis. Results/methodology: Fast and sensitive methods for determination of seven clinically relevant statins, their interconversion products and metabolites (17 analytes in total) in biological samples using microextraction by packed sorbent for sample preparation and UHPLC-MS/MS for subsequent analysis were developed and validated. Three MS platforms with different ion sources, transfer optics, collision cell technologies and scan speed parameters were compared. CONCLUSION: Significant differences among the methods were observed in terms of selectivity and sensitivity. Microextraction by packed sorbent was successful in the extraction of all 17 analytes from biological matrix.

• MeSH
• Blood Chemical Analysis methods   MeSH
• Chemical Precipitation MeSH
• Humans MeSH
• Limit of Detection MeSH
• Solid Phase Microextraction methods   MeSH
• Reproducibility of Results MeSH
• Hydroxymethylglutaryl-CoA Reductase Inhibitors blood   chemistry   isolation & purification   MeSH
• Tandem Mass Spectrometry methods   MeSH
• Chromatography, High Pressure Liquid methods   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH

The study compared the ability of various chemical methods (XAD, β-hydroxypropylcyclodextrin - HPCD) and solid phase micro-extraction (SPME)) to mimic earthworm uptake from two similar soils containing either spiked or aged p,p´-DDE, thus representing two extreme scenarios with regard to the length of pollutant-soil contact time and the way of contamination. The extent of bioaccumulation was assessed at fixed exposure periods (10 and 21 days) and at equilibrium derived from uptake curves by multiple-point comparison or kinetic modeling. The decision on the best chemical predictor of biological uptake differed. The degree of bioaccumulation at equilibrium was best predicted by XAD while HPCD rather reflected the extent of accumulation derived after 21 days when, however, steady-state was not reached for spiked p,p´-DDE. SPME seemed to underestimate the uptake of aged p,p´-DDE, probably of the fraction taken up via soil particles. Thus, the degree of predictability seems to be associated with the capability of the chemical method to mimic the complex earthworm uptake via skin and intestinal tract as well as with the quality of biological data where the insufficient length of exposure period appears to be the major concern.

• MeSH
• beta-Cyclodextrins chemistry   MeSH
• Dichlorodiphenyl Dichloroethylene analysis   MeSH
• Soil Pollutants analysis   MeSH
• Solid Phase Microextraction methods   MeSH
• Environmental Monitoring methods   MeSH
• Oligochaeta drug effects   metabolism   MeSH
• Polystyrenes chemistry   MeSH
• Soil chemistry   MeSH
• Environmental Pollution analysis   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH

Methods for the separation and determination of terpenes (mono- and sesqui-) and phenylpropanoids such as eugenol and methyleugenol from samples of allspice berries have been developed. Chromatographic analyses of isolated groups of compounds were carried out by means of gas chromatography coupled with mass spectrometry. A comparison of various types of solid-phase microextraction fibers was performed. The highest yields of terpenes were extracted by polydimethylsiloxane and divinylbenzene/Carboxen/polydimethylsiloxane fibers (almost the same for these two fibers), approximately twice as much as by Carbowax/divinylbenzene fiber. The highest amounts of monoterpenes were extracted by divinylbenzene/Carboxen/polydimethylsiloxane fiber, and the highest amounts of sesquiterpenes were extracted by polydimethylsiloxane fiber. Moreover, the effect of water addition on extraction yields as well as time and temperature of extraction were tested. Aroma profiles of extracts obtained by solid-phase microextraction and essential oil obtained by hydrodistillation of allspice berries were compared. The aroma profile of the divinylbenzene/Carboxen/polydimethylsiloxane fiber extract was similar to the aroma profile of essential oil. Particular characteristics of volatile allspice matters were presented. The linear retention indices for each compound were calculated.

• MeSH
• Distillation MeSH
• Dimethylpolysiloxanes chemistry   MeSH
• Solid Phase Microextraction methods   MeSH
• Monoterpenes chemistry   MeSH
• Oils, Volatile MeSH
• Pimenta chemistry   MeSH
• Gas Chromatography-Mass Spectrometry methods   MeSH
• Polyethylene Glycols chemistry   MeSH
• Sesquiterpenes chemistry   MeSH
• Temperature MeSH
• Terpenes analysis   chemistry   MeSH
• Vinyl Compounds chemistry   MeSH
• Water chemistry   MeSH
• Publication type
• Journal Article MeSH

A novel approach for automation of Micro-Extraction by Packed Sorbent (MEPS), a solid phase extraction technique, is presented, enabling precise and repeatable liquid handling due to the employment of sequential injection technique. The developed system was used for human urine sample clean-up and pre-concentration of betaxolol before its separation and determination. A commercial MEPS C-18 cartridge was integrated into an SIChrom™ system. The chromatographic separation was performed on a monolithic High Resolution C18 (50×4.6 mm) column which was coupled on-line in the system with Micro-Extraction using an additional selection valve. A mixture of acetonitrile and aqueous solution of 0.5% triethylamine with acetic acid, pH adjusted to 4.5 in ratio 30:70 was used as a mobile phase for elution of betaxolol from MEPS directly onto the monolithic column where the separation took place. Betaxolol was quantified by a fluorescence detector at wavelengths λ(ex)=220 nm and λ(em)=305 nm. The linear calibration range of 5-400 ng mL(-1), with limit of detection 1.5 ng mL(-1) and limit of quantification 5 ng mL(-1) and correlation r=0.9998 for both the standard and urine matrix calibration were achieved. The system recovery was 105±5%; 100±4%; 108±1% for three concentration levels of betaxolol in 10 times diluted urine - 5, 20 and 200 ng mL(-1), respectively.

• MeSH
• Urinalysis instrumentation   methods   MeSH
• Betaxolol isolation & purification   urine   MeSH
• Chromatography methods   MeSH
• Equipment Design MeSH
• Spectrometry, Fluorescence MeSH
• Injections * MeSH
• Humans MeSH
• Solid Phase Microextraction methods   MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH