High throughput determination of free biogenic monoamines and their metabolites in urine using thin-film solid phase microextraction.

UPLC-MS/MS methods are the gold standard for routine, high-throughput measurements of biogenic monoamines for the diagnosis of catecholamine-producing tumors. However, this cannot be achieved without employing efficient sample pretreatment methods. Therefore, two pretreatment methods, thin-film solid phase microextraction (TF-SPME) and packed fibers solid phase extraction (PFSPE), were developed and evaluated for the analysis of biogenic monoamines and their metabolites in urine. A hydrophilic-lipophilic balance (HLB) coating was chosen for the thin-film blade format SPME method and compared with a Polycrown ether (PCE) composite nanofiber used as an adsorbent for the PFSPE method. Under optimal conditions, the absolute extraction recovery and relative matrix effect of the newly developed TF-SPME method were determined to be 35.7-74.8% and 0.47-3.63%, respectively. The linearity was 0.25-500 ng mL-1 for norepinephrine, epinephrine, dopamine, normetanephrine 3-methoxytyramine, serotonin, histamine, and 0.1-500 ng mL-1 for metanephrine. The intra-and inter-assay coefficients of variation were 0.7-8.7%, and the respective accuracies were calculated to be 90.8-104.7% and 89.5-104.5% for TF-SPME. Compared with the PFSPE method, the TF-SPME method had a higher extraction efficiency, lower matrix effects and a wider linear range for eight target substances, which ensured higher accuracy of simultaneous detection of all compounds of interest. Therefore, the proposed TF-SPME method can be employed for the high throughput screening for neuroendocrine tumors in a routine clinical setting and other relative research by simultaneous quantitation of urine eight biological monoamines in a single run.

Overcoming matrix effects in the analysis of pyrethroids in honey by a fully automated direct immersion solid-phase microextraction method using a matrix-compatible fiber.

Pyrethroids insecticides may constitute a major hazard to honeybees, leading to colony collapse disorder. However, the determination of pyrethroids in honey has remained a challenging undertaking for analysts to date due to the high complexity of this matrix as well as the MRLs. This paper presents a fully automated method to overcome matrix influences using matrix-compatible overcoated SPME fiber for quantitative analysis of pyrethroids in diluted honey by GC-MS. The developed method was optimized using a multivariate approach providing LOQ values much lower than the stablished MRL (0.10-10 ng/g), while granting satisfactory linearity (R2 > 0.998) in a wide linear range of 0.1-2000 ng/g, repeatability with RSDs < 10%, reproducibility RSDs < 20%, and accuracy ranging from 75 to 118% and from 82 to 120 % for inter-day and intra-day assays, respectively by using five replicates. The method herein proposed overcomes challenges presented by complex matrices while minimizing sample handling and the overall complexity of the procedure.

Rapid and high-throughput screening of multi-residue pharmaceutical drugs in bovine tissue using solid phase microextraction and direct analysis in real time-tandem mass spectrometry (SPME-DART-MS/MS).

Direct Analysis in Real Time (DART) has become a popular research area in food safety monitoring due to its unique characteristics that allow rapid and high-throughput screening of complex matrices with minimal sample preparation. The current research aimed to investigate the detection and quantitation capabilities of solid phase microextraction (SPME) and DART coupled to tandem mass spectrometry MS/MS for a large number of pharmaceutical drugs covering a wide range of physico-chemical properties (log P, -1.22-5.97) in complex animal-food matrices such as beef tissue. 53% of the 98 target analytes selected initially could be efficiently ionized by DART and quantified at or below the Canadian maximum residue limits (MRLs) and US regulatory tolerances in bovine muscle. Despite using only two internal standards for correction, promising results were obtained for these analytes, where 62% of the detected analytes achieved linear correlation coefficients >0.99 within the evaluated range of concentrations (0.25-3X, where X corresponds to the MRL for each target analyte). In addition, more than 92% of the detected analytes achieved average accuracies within the 70-120% range of their true concentrations and intraday repeatability RSDs ≤25% at the 0.5X, 1X, and 2X concentration levels. The fully automated sample preparation workflow allowed for total extraction and analysis times as short as 1 min time per sample. While DART has limited capabilities in terms of analyte coverage, this research highlights the potential usefulness of SPME-DART-MS/MS as a method for rapid analysis in food safety monitoring applications.

Optimization of Coated Blade Spray for Rapid Screening and Quantitation of 105 Veterinary Drugs in Biological Tissue Samples.

Rapid and efficient determination of contaminants at trace levels in tissue samples has become an unmet need around the globe. Coated blade spray (CBS) extraction/ionization is a technology capable of performing, with a single device, enrichment of analytes present in complex matrices, as well as the direct interface and introduction of said analytes into the mass spectrometer via electrospray ionization. To facilitate the challenging rapid tissue screening, we describe for the first time the use of a very thin layer of biocompatible polyacrylonitrile as a CBS device undercoating to make metal surface biocompatible. This add-on is meant to protect the portion of the uncoated stainless-steel of the blade that is normally exposed to the matrix, consequently becoming susceptible to adhesion of matrix macromolecules, cells, and fat. In addition, we present for the first time the use of CBS in negative ionization mode for quantitative purposes. The optimized CBS workflow allows for rapid and high-throughput screening and quantitation of 105 veterinary drugs in homogenized bovine tissue in both negative and positive ionization mode in one single run using a single CBS device with analysis times as short as 1 min per sample when 96 extractions are simultaneously conducted. While only two internal standards were used for correction, one per ionization mode, excellent accuracy and precision were achieved, with more than 90% of analytes falling within the 70-120% range of their true concentrations and yielding RSD ≤ 25% at three validation levels. The majority of analytes achieved linear correlation coefficients >0.99, and all 105 analytes were able to meet both Canadian and U.S. regulatory levels.

Comparison of Solid-Phase Microextraction to Solvent Extraction and QuEChERS for Quantitative Analysis of Veterinary Drug Residues in Chicken and Beef Matrices.

A fully automated high-throughput method using solid-phase microextraction (SPME) was developed and validated for quantitative analysis of more than 100 veterinary drugs in chicken and beef tissue. The work also encompassed a comparison of the SPME method to two well-documented sample preparation procedures, solvent extraction (SE) and quick, easy, cheap, effective, rugged, and safe (QuEChERS). SPME showed considerably less matrix effects, with only two compounds showing significant matrix effects in comparison to 30% of analytes in QuEChERS and 42% in SE in beef tissue. Excellent accuracy and precision results were achieved with all methods in the chicken matrix, with more than 91% of analytes falling within the 70-120% range of their true concentrations and relative standard deviation of ≤25% at 0.75X and 1.5X, where X is the maximum residue level. Similar results were achieved in beef tissue. All methods were able to meet regulatory limit of quantitation levels for the majority of target analytes.

Development and validation of a fully automated solid phase microextraction high throughput method for quantitative analysis of multiresidue veterinary drugs in chicken tissue.

This paper presents the development and validation of a fully automated, high-throughput multiclass, multiresidue method for quantitative analysis of 77 veterinary drugs in chicken muscle via direct immersion solid phase microextraction (DI-SPME) and ultra-high pressure liquid chromatography-electrospray ionization - tandem mass spectrometry (UHPLC-ESI-MS/MS). The selected drugs represent more than 12 different classes of drugs characterized by varying physical and chemical properties. A Hydrophilic-lipophilic balance (HLB)/polyacrylonitrile (PAN) extraction phase, prepared using HLB particles synthesized in-house, yielded the best extraction/desorption performance among four different SPME extraction phases evaluated in the current work. The developed SPME method was optimized in terms of SPME coating and geometry, desorption solvent, extraction and rinsing conditions, and extraction and desorption times. Multivariate analysis was performed to determine the optimal desorption solvent for the proposed application. The developed method was validated according to the Food and Drug Administration (FDA) guidelines, taking into account Canadian maximum residue limits (MRLs) and US maximum tolerance levels for veterinary drugs in meat. Method accuracy ranged from 80 to 120% for at least 73 compounds, with relative standard deviation of 1-15%. Inter-day precision ranged from 4 to 15% for 70 compounds. Determination coefficients values were higher than 0.991 for all compounds under study with no significant lack of fit (p > 0.05) at the 5% level. In terms of limits of quantitation, the method was able to meet both Canadian and US regulatory levels for all compounds under study.