Application of carbon nanosorbent for PRiME pass-through cleanup of 10 selected local anesthetic drugs in human plasma samples

Nano-titania modified cupric-based metal–organic frameworks for the on-line pass-through cleanup of phenothiazine drugs and metabolites in human plasma

SEM (A) and TEM (B) images of NTMCu-MOFs.

Isocyanate derivatization coupled with phospholipid removal microelution-solid phase extraction for the simultaneous quantification of (S)-metoprolol and (S)-α-hydroxymetoprolol in human plasma with LC-MS/MS

A sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay was developed and validated for the quantification of (S)-metoprolol (MET) and its main metabolite, (S)-α-hydroxymetoprolol (OH-MET). Human plasma samples (50 μL) were spiked with both analytes and their deuterated internal standards (IS) (S)-MET-(d7) and α-OH-MET-(d5). Phospholipid removal microelution-solid phase extraction (PRM-SPE) was performed using a 4-step protocol with Oasis PRiME MCX μElution 96-well cartridges. The eluates were reconstituted in 100 μL of acetonitrile with 50 μg/mL (S)-α-methylbenzyl isocyanate (MBIC) for chiral derivatization. After 60 min at room temperature, the reaction was quenched using 100 μL of water 2 % formic acid. Chromatographic separation of the derivatized analytes was performed on a Kinetex phenyl-hexyl core-shell stationary phase with an elution gradient. Mobile phases were composed of a mixture of water and methanol, with ammonium formate and formic acid as buffers. Total runtime was 15 min. Analyte detection was performed by an AB/SCIEX 4000 QTRAP mass spectrometer with multiple reaction monitoring. Chromatograms showed MBIC successfully reacted with racemic MET, α-OH-MET, and their respective IS. Detection by positive electrospray ionization did not reveal derivatized by-products. Quantification ranges were validated for (S)-MET and (S)-α-OH-MET between 0.5-500 and 1.25-500 ng/mL, respectively, with correlation coefficients (r²) >0.9906. The PRM-SPE assay showed low matrix effects (86.9-104.0 %) and reproducible recoveries (69.4-78.7 %) at low, medium, and high quality control (QC) levels. Precision and accuracy were all comprised between 85-115 % for all three QCs, and between 80-120 % for the lower limit of quantification, for intra- and inter-day values (n = 6, 3 consecutive days). Non-derivatized analytes were stable at room temperature, after 3 freeze-thaw cycles, and stored for 30 days at -80 °C (n = 4). Reinjection reproducibility of a previously validated batch was achieved after 8 days under auto-sampler conditions, indicating the stability of (S)-MET and (S)-α-OH-MET derivatives. Its clinical use was established in a cohort of 50 patients and could be used to further investigate the clinical impact of (S)-MET concentrations.

Application of petal-shaped ionic liquids modified covalent organic frameworks for one step cleanup and extraction of general anesthetics in human plasma samples

Here, the novel petal-shaped ionic liquids modified covalent organic frameworks (PS-IL-COFs) particles have been synthesized by using ionic liquids as modifying agent, which could be beneficial to avoid the aggregation of COFs during the preparation and improve its dispersing performance. The novel PS-IL-COFs particles have been used and evaluated in the one step cleanup and extraction (OSCE) procedure for human plasma prior to the analysis of 3 general anesthetics by liquid chromatography-tandem quadrupole mass spectrometry (LC-MS/MS). In the OSCE procedure, human plasma samples are directly mixed with extraction solvent and PS-IL-COFs particles, and the extraction and cleanup procedure have been carried out simultaneously. Compared with the Oasis PRiME HLB cartridge method, the OSCE procedure using PS-IL-COFs particles as sorbents is much more effective for the minimization of ion suppression resulted from blood phospholipids. Under optimal conditions, the PS-IL-COFs particles show higher cleanup efficiency of 3 general anesthetics with recoveries in the range of 82.5%-115%. The limits of quantification (LOQs) for propofol, ketamine and etomidate are 0.18 μg/L, 0.15 μg/L and 0.016 μg/L, respectively. Validation results on linearity, specificity, precision and trueness, as well as on the application to analysis of general anesthetics in a case of a 54-year-old female suffered gallstone demonstrate the applicability to clinical studies.

Simultaneous determination of ten aminoglycoside antibiotics in aquatic feeds by high-performance liquid chromatography quadrupole-orbitrap mass spectrometry with pass-through cleanup

A simple and sensitive method has been established based on pass-through cleanup and high-performance liquid chromatography quadrupole-orbitrap mass spectrometry (HPLC-Q/Orbitrap MS) for the simultaneous determination of ten aminoglycosides (AGs) in aquatic feeds. The extraction solution and cleanup procedure had been optimized, and good sensitivity, accuracy, and precision were obtained. The calibration curves of AGs were linearity (R² > 0.99) in the range of 2.0 to 200 μg/L (or 5.0 to 500 μg/L). The limits of detection of AGs were between 10 and 25 μg/kg. The recoveries of AGs ranged from 74.9% to 94.3%, and the intraday and interday relative standard deviations were less than 15%. Finally, this method was successfully applied to determine ten AGs in 30 aquatic feed samples. It might be the first time to use pass-through cleanup approach combined with HPLC-Q/Orbitrap MS method for AGs determination in aquatic feed samples.

PRiME pass-through purification of lignans in Silybum marianum and UPLC-MS/MS analysis

A PRiME (process, robustness, improvements, matrix effects, ease of use) pass-through cleanup procedure was developed for the extraction and purification of silychristins A and B, silybins A and B, isosilybins A and B, and silydianin in Silybum marianum. After optimizing the extracting solvent types and the sample loading volume, the crude extract was diluted to 3 mL with 95% acetonitrile and then loaded on the PRiME cartridge. The eluate was analyzed by ultra-performance liquid chromatography and tandem mass spectrometry (UPLC-MS/MS). All the target analytes were deprotonated as [M-H]- at m/z 481 by conducting collision-induced dissociation (CID), and the major fragment ions were m/z 463 ([M-H2O-H]-), 453 ([M-CO-H]-), 355 ([M-C6H6O3-H]-), 301 ([M355-CO2-H]-), and 179 ([C10H11O3]-). Afterwards, this method was validated in terms of linearity (R2 > 0.9990), intra-day precision (1.02%-3.79%), inter-day precision (1.59%-4.87%), sensitivity (LOD ≤ 0.45 μg·kg-1 and LOQ ≤ 1.50 μg·kg-1), and recovery (76.9-103.4%, RSD < 8.90%). Finally, the proposed protocol was successfully applied to eight batches of S. marianum samples. The total content of the seven active compounds varied amongst the batches from different places of origin.