scholarly journals Electrospray tandem mass spectrometric measurements of organotin compounds

2004 ◽  
Vol 18 (1) ◽  
pp. 95-112 ◽  
Author(s):  
Joseph H. Banoub ◽  
Judith Miller-Banoub ◽  
George V. Sheppard ◽  
Howard J. Hodder

Electrospray mass spectrometry of a series of organotin compounds in solutions of methanol are reported. Low energy collision‒induced dissociation MS/MS analysis of diagnostic precursor ions confirmed the characteristic fingerprint patterns obtained in the conventional electrospray spectra and proved to be a specific and very sensitive method for quantification of the (R3Sn)2O and the series of RnSnX4–ncompounds in environmental matrices. Concentrations of butyltin compounds (TBTX, DBTX2and MBTX3) in sediment reference materials PACS-1 and PACS-2 and butyltin and phenyltin compounds (TBTX, DBTX2, MBTX3, TPTX, DPTX2and DPTX3) in Quasimeme II biota reference material (QSP001BT) were determined. The organotin compounds were extracted from the reference materials with 1-butanol followed by dilution with methanol containing 1 mM ammonium acetate. The extracts were introduced directly into the electrospray source by a continuous flow of MeOH : H2O (60 :40). Quantitation of TBTX, DBTX2, TPTX, DPTX2and DPTX3was achieved by low energy CID tandem mass spectrometry using the Multiple Reaction Monitoring (MRM) analysis with the appropriate MS/MS transitions (positive ion electrospray ionization). Quantitation of MBTX3was achieved using a negative ion electrospray CID tandem mass spectrometry method. For all samples quantitation was achieved by use of the method of standard addition, relative extraction recoveries were determined spiking with internal standards of mono‒, di‒ and triorganotin compounds separately to different samples.

2019 ◽  
Vol 15 (7) ◽  
pp. 710-715
Author(s):  
S.T. Narenderan ◽  
Basuvan Babu ◽  
T. Gokul ◽  
Subramania Nainar Meyyanathan

Objective: The aim of the present work is to achieve a novel highly sensitive chromatographic method for the simultaneous determination of hepatitis C agents, sofosbuvir and velpatasvir from human plasma using ritonavir as an internal standard. Methods: Chromatographic separation was achieved using Hypersil C18 column (50mm x 4.6mm, 3μm) with an isocratic elution mode using the mobile phase composition 10 mM ammonium formate buffer (pH 5.0): acetonitrile (20:80 v/v) pumped at a flow rate of 0.5 ml/min. The detection was carried out by tandem mass spectrometry using Multiple Reaction Monitoring (MRM) positive Electrospray Ionization (ESI) with proton adducts at m/z 530.10 > 243.10, 883.40 > 114.0 and 721.25 > 197.0. Results: The method validated as per USFDA guidelines with respect to linearity, accuracy, and precision was found to be acceptable over the concentration range of 0.2–2000 ng/ml and 5-2000 ng/ml for sofosbuvir and velpatasvir respectively and the method was found to be highly sensitive and selective. Conclusion: The developed tandem mass spectrometric method is robust and can be applied for the monitoring of plasma levels of the analyzed drug in preclinical and clinical pharmacokinetic studies.


Pharmaceutics ◽  
2018 ◽  
Vol 10 (3) ◽  
pp. 123 ◽  
Author(s):  
Lingzhi Wang ◽  
Do-Dang Phan ◽  
Nicholas Syn ◽  
Xiaoqiang Xiang ◽  
Hongyan Song ◽  
...  

A sensitive and robust liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed and validated for the determination of nimbolide in mouse serum. Exemestane was used as the internal standard (IS). Here, we employed acetonitrile-based protein precipitation (PPT) for serum sample preparation, and performed chromatographic separation using an ODS Hypersil C18 column (100 mm × 2.1 mm, 5 µm) with gradient elution (0.1% formic acid in water vs 100% acetonitrile). The run time was 6 min. Instrumental analysis was performed by electrospray ionization tandem mass spectrometry (ESI-MS/MS) in the multiple-reaction monitoring (MRM) under positive mode. A good linear calibration was achieved in the 5–1000 ng/mL range. The intra- and inter-day precisions for nimbolide were ≤12.6% and ≤13.9% respectively. Intra-day accuracy ranged from 96.9–109.3%, while inter-day accuracy ranged from 94.3–110.2%. The matrix effect of nimbolide, detected but consistent at low and high concentrations, do not affect linearity of standard curve. In conclusion, we have developed and validated a sensitive analytical method for determination of a novel natural compound nimbolide in mouse serum, and it has been successfully applied to our preclinical study in investigating the pharmacokinetic properties of nimbolide, which could greatly facilitate the preclinical development of the promising lead compound for anticancer therapy.


2007 ◽  
Vol 53 (2) ◽  
pp. 292-299 ◽  
Author(s):  
Mireia Urpi-Sarda ◽  
Raul Zamora-Ros ◽  
Rosa Lamuela-Raventos ◽  
Antonio Cherubini ◽  
Olga Jauregui ◽  
...  

Abstract Background: Nutritional biomarkers are alternatives to traditional dietary assessment tools. We sought to develop a method for nutritional analysis of resveratrol, a phenolic compound with purported health-promoting properties, and to determine all resveratrol metabolites. Methods: We obtained LDL and urine samples from 11 healthy male volunteers who had consumed 250 mL of Merlot red wine. We measured resveratrol and its metabolites with 96-well solid-phase extraction plates coupled with HPLC-tandem mass spectrometry. Hexestrol was used as the internal standard. Gradient chromatography in multiple reaction monitoring mode was performed on a Luna C18 column, maintained at 40 °C; m/z transitions were as follows: resveratrol, 227/185; resveratrol glucosides, 389/227; resveratrol glucuronides, 403/227; resveratrol sulfates, 307/227; taxifolin, 303/285; and hexestrol, 269/134. Results: Standard calibration curves were linear at 4.4–3289.5 nmol/L. Residual analyses were 100% (3.2) for trans-resveratrol and 100% (11.1) for trans-piceid. In both matrices, imprecision (CV) was <10.8% at all concentrations. Detection limits for resveratrol were 0.2 nmol/L (LDL), 0.3 nmol/L (synthetic urine), and 4.0 nmol/L (blank urine). Resveratrol and metabolites were checked for stability, and no degradation was observed. Conclusions: The HPLC–tandem mass spectrometry method enabled us to identify resveratrol sulfates in human LDL and to characterize the complete profile of resveratrol metabolism in human LDL and urine. This method provides an accurate index of exposure to resveratrol and its metabolites, which can be used as nutritional biomarkers for evaluating the biological effects of moderate wine intake on human health.


2002 ◽  
Vol 48 (11) ◽  
pp. 1970-1980 ◽  
Author(s):  
James J Pitt ◽  
Mary Eggington ◽  
Stephen G Kahler

Abstract Background: Detection of abnormal metabolites in urine is important for the diagnosis of many inborn errors of metabolism (IEM). Rapid, comprehensive screening methods are needed. Methods: We used electrospray ionization tandem mass spectrometry in positive- and negative-ion modes to detect selected metabolites in urine. For positive-ion analysis, samples were dried and butylated, whereas for negative-ion analysis, samples were merely diluted with the mobile phase. Analysis was by direct injection with multiple reaction monitoring for 32 metabolites in positive mode (amino acids and acylcarnitines) and 30 metabolites in negative mode (organic acids). Run time was 2.1 min in each mode. Results: Interbatch CVs ranged from 4.8% to 32%, enabling quantification of many metabolites. The procedure was applied to controls (278 and 120 in positive- and negative-ion mode, respectively) and 108 IEM individuals representing 37 different IEM. In 105 IEM individuals, representing 36 different IEM, concentrations of one or more diagnostic metabolites were above the 99th percentiles of the control values. Conclusions: The procedure is faster and less labor-intensive than conventional methods of testing for IEM by amino and organic acid profiling and has similar diagnostic sensitivity. The ability to include a greater range of metabolites offers the potential of a more comprehensive screening procedure.


2002 ◽  
Vol 85 (4) ◽  
pp. 841-847 ◽  
Author(s):  
Xiaoming Fang ◽  
Jiahua Chen ◽  
Dehua Guo ◽  
Guoquan Wang

Abstract A sensitive, specific, and reliable liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed for detection and identification of zeranol in chicken or rabbit liver. A homogenized liver sample was hydrolyzed with β-glucuronidase/arylsulfatase, and the hydrolysate was extracted with ethyl ether. The supernatant was evaporated to dryness, and the residue was dissolved in chloroform and re-extracted with sodium hydroxide. After acidification, the extract was cleaned up on a C18 solid-phase extraction cartridge and analyzed by electrospray LC-MS/MS in the negative ion mode. The multiple reaction monitoring transition from both m/z 321 to 277 and m/z 321 to 303 was monitored for confirmation, and the product ion of 277 was used for quantitation. Separation was performed on a Waters XTettra™ C18 column (50 × 2.1 mm, 3.5 μm) combined with a safeguard column (Symmetry C18, 20 × 3.9 mm, 5 μm), using a gradient elution with acetonitrile and 20mM ammonium acetate. Calibration curves were prepared and good linearity was achieved over the concentration ranges tested. For all liver samples fortified at 3 different levels of 1, 5, and 50 μg/kg, the overall recoveries and relative standard deviations were in the range of 61–90 and 8–13%, respectively. The limit of quantitation based on the assay validation was 1 μg/kg. The method had been used on a routine basis for detection and identification of zeranol in liver samples.


2021 ◽  
Vol 413 (23) ◽  
pp. 5901-5920
Author(s):  
Elizabeth Holton ◽  
Barbara Kasprzyk-Hordern

AbstractThis manuscript describes a new multiresidue method utilising ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) via multiple reaction monitoring (MRM), for the identification and quantification of 58 antibiotics and their 26 metabolites, in various solid and liquid environmental matrices. The method was designed with a ‘one health’ approach in mind requiring multidisciplinary and multisectoral collaborative efforts. It enables comprehensive evaluation of antibiotic usage in surveyed communities via wastewater-based epidemiology, as well as allowing for the assessment of potential environmental impacts. The instrumental performance was very good, demonstrating linearity up to 3000 μg L−1, and high accuracy and precision. The method accuracy in several compounds was significantly improved by dividing calibration curves into separate ranges. This was accompanied by applying a weighting factor (1/x). Microwave-assisted and/or solid-phase extraction of analytes from liquid and solid matrices provided good recoveries for most compounds, with only a few analytes underperforming. Method quantification limits were determined as low as 0.017 ng L−1 in river water, 0.044 ng L−1 in wastewater, 0.008 ng g−1 in river sediment, and 0.009 ng g−1 in suspended solids. Overall, the method was successfully validated for the quantification of 64 analytes extracted from aqueous samples, and 45 from solids. The analytes that underperformed are considered on a semi-quantitative basis, including aminoglycosides and carbapenems. The method was applied to both solid and liquid environmental matrices, whereby several antibiotics and their metabolites were quantified. The most notable antibiotic-metabolite pairs are three sulfonamides and their N-acetyl metabolites; four macrolides/lincomycins and their N-desmethyl metabolites; and five quinolone metabolites. Graphical abstract


2013 ◽  
Vol 57 (4) ◽  
pp. 567-572 ◽  
Author(s):  
Katarzyna Pietruszka ◽  
Bartosz Sell ◽  
Olga Burek ◽  
Henryka Wiśniewska-Dmytrow

Abstract A multiresidue method for determination and quantification of Fusarium mycotoxins: deoxynivalenol, zearalenone, T-2 toxin, HT-2 toxin, and metabolite of Aspergillus and Penicillium species - ochratoxin A in feeds was described. The method was based on the simultaneous extraction of selected mycotoxins from matrix, followed by liquid chromatography coupled with tandem mass spectrometry using a hybrid triple quadrupole - linear ion trap mass spectrometer with the multiple reaction monitoring in both positive- and negative-ion modes. The method was validated in accordance with the Commision Decision 2002/657/EC requirements. The mean recoveries of mycotoxins from spiked feed samples ranged from 74.6% to 113.9%, whereas limit of detection and quantification ranged from 0.72 to 12.4 μg/kg and 1.86 to 31.7 μg/kg, respectively.


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