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Merkley ED, Burnum-Johnson KE, Anderson LN, Jenson SC, Wahl KL. Uniformly 15N-Labeled Recombinant Ricin A-Chain as an Internal Retention Time Standard for Increased Confidence in Forensic Identification of Ricin by Untargeted Nanoflow Liquid Chromatography-Tandem Mass Spectrometry. Anal Chem 2019; 91:13372-13376. [PMID: 31596564 DOI: 10.1021/acs.analchem.9b03389] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Ricin, a toxic protein from the castor plant, is of forensic and biosecurity interest because of its high toxicity and common occurrence in crimes and attempted crimes. Qualitative methods to detect ricin are therefore needed. Untargeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) proteomics methods are well suited because of their high specificity. Specificity in LC-MS/MS comes from both the LC and MS components. However, modern untargeted proteomics methods often use nanoflow LC, which has less reproducible retention times than standard-flow LC, making it challenging to use retention time as a point of identification in a forensic assay. We address this challenge by using retention times relative to a standard, namely, the uniformly 15N-labeled ricin A-chain produced recombinantly in a bacterial expression system. This material, added as an internal standard prior to trypsin digestion, produces a stable-isotope-labeled standard for every ricin tryptic peptide in the sample. We show that the MS signals for 15N and natural isotopic abundance ricin peptides are distinct, with mass shifts that correspond to the numbers of nitrogen atoms in each peptide or fragment. We also show that, as expected, labeled and unlabeled peptides coelute, with relative retention time differences of less than 0.2%.
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Affiliation(s)
- Eric D Merkley
- Chemical and Biological Signature Sciences Group , Pacific Northwest National Laboratory , Richland , Washington 99354 , United States
| | - Kristin E Burnum-Johnson
- Integrative Omics Group , Pacific Northwest National Laboratory , Richland , Washington 99354 , United States
| | - Lindsey N Anderson
- Biological Systems Science Group , Pacific Northwest National Laboratory , Richland , Washington 99354 , United States
| | - Sarah C Jenson
- Chemical and Biological Signature Sciences Group , Pacific Northwest National Laboratory , Richland , Washington 99354 , United States
| | - Karen L Wahl
- Integrative Omics Group , Pacific Northwest National Laboratory , Richland , Washington 99354 , United States
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2
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Stulz R, Meuller J, Baždarević D, Wennberg Huldt C, Strömberg R, Andersson S, Dahlén A. A Versatile and Convenient Synthesis of 34 S-Labeled Phosphorothioate Oligonucleotides. Chembiochem 2018; 19:2114-2119. [PMID: 30062829 PMCID: PMC6585993 DOI: 10.1002/cbic.201800417] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Indexed: 12/20/2022]
Abstract
A synthetic protocol for 34 S-labeled phosphorothioate oligonucleotides (PS ONs) was developed to facilitate MS-based assay analysis. This was enabled by a highly efficient, two-step, one-pot synthesis of 34 S-labeled phenylacetyl disulfide (34 S-PADS), starting from 34 S-enriched elemental sulfur (34 S8 ). 34 S-PADS was subsequently used for stable isotope labeling (SIL) of oligonucleotides containing a phosphorothioate backbone. The 34 S-SIL PS ONs are shown to retain the same melting temperature, antisense activity, and secondary structure as those of the corresponding unlabeled 32 S PS ONs.
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Affiliation(s)
- Rouven Stulz
- Cardiovascular, Renal and Metabolism IMED Biotech Unit, AstraZeneca, Pepparedsleden 1, 43150, Mölndal, Sweden.,Department of Biosciences and Nutrition, Karolinska Institutet, NEO, Hälsovägen 9, 14157, Huddinge, Sweden
| | - Johan Meuller
- Discovery Sciences IMED Biotech Unit, AstraZeneca, Pepparedsleden 1, 43150, Mölndal, Sweden
| | - Dženita Baždarević
- Cardiovascular, Renal and Metabolism IMED Biotech Unit, AstraZeneca, Pepparedsleden 1, 43150, Mölndal, Sweden
| | - Charlotte Wennberg Huldt
- Cardiovascular, Renal and Metabolism IMED Biotech Unit, AstraZeneca, Pepparedsleden 1, 43150, Mölndal, Sweden
| | - Roger Strömberg
- Department of Biosciences and Nutrition, Karolinska Institutet, NEO, Hälsovägen 9, 14157, Huddinge, Sweden
| | - Shalini Andersson
- Cardiovascular, Renal and Metabolism IMED Biotech Unit, AstraZeneca, Pepparedsleden 1, 43150, Mölndal, Sweden
| | - Anders Dahlén
- Cardiovascular, Renal and Metabolism IMED Biotech Unit, AstraZeneca, Pepparedsleden 1, 43150, Mölndal, Sweden
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Mohamed AMI, Abdel-Wadood HM, Mousa HS. Dual design spaces for micro-extraction together with the core–shell chromatographic determination of dorzolamide and timolol in rabbit plasma: an example of quality by design method development. NEW J CHEM 2016. [DOI: 10.1039/c5nj03719k] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An innovative quality by design-integrated VA-SALLME-core–shell chromatographic method was developed for the simultaneous determination of DOR and TIM in plasma.
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Affiliation(s)
| | | | - Heba Salah Mousa
- Pharmaceutical Analytical Chemistry
- Faculty of Pharmacy
- South Valley University
- Egypt
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4
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Lausecker B, Fischer G. Development of a liquid chromatographic/tandem mass spectrometric assay for a new endothelin receptor antagonist, and its application to dog plasma samples generated after simultaneous i.v. and p.o. administration of the unlabeled and deuterium-labeled forms of this antagonist. JOURNAL OF MASS SPECTROMETRY : JMS 2003; 38:649-658. [PMID: 12827634 DOI: 10.1002/jms.479] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
An assay was developed and applied to determine the bioavailability of a new endothelin receptor antagonist after simultaneous p.o. and i.v. administration of the drug and its stable isotope-labeled analogue. The drug, its main metabolite and the stable isotope-labeled analogues of the drug and the main metabolite were quantified in dog plasma samples using a structural analogue as internal standard. In addition to the calculation of the bioavailability, the formation of the metabolite after p.o. and i.v. administration could be followed independently. The assay covered the concentration range 0.25-1000 ng ml(-1) using sample aliquots of only 50 micro l. Plasma samples were processed after protein precipitation with on-line solid-phase extraction, narrow-bore high-performance liquid chromatography and subsequent tandem mass spectrometric detection. Detection was accomplished with ionspray in the positive ion selected reaction monitoring mode. The inter-assay precision and accuracy of the assay were in the range 4.7-14.2% and 90.3-113.3%, respectively, and the intra-assay precision and accuracy were in the range 1.4-11.5% and 88.4-112.5%, respectively. The fragmentation of the drug was investigated and showed an unexpected shift of a methyl group. Data from MS(n), medium-resolution exact mass tandem mass spectrometry and H-D exchange experiments were employed to clarify the mechanism.
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Affiliation(s)
- B Lausecker
- F. Hoffmann-La Roche, Ltd, Non-Clinical Drug Safety, P.O. Box, CH-4070 Basel, Switzerland.
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Chavez-Eng CM, Constanzer ML, Matuszewski BK. High-performance liquid chromatographic-tandem mass spectrometric evaluation and determination of stable isotope labeled analogs of rofecoxib in human plasma samples from oral bioavailability studies. J Chromatogr B Analyt Technol Biomed Life Sci 2002; 767:117-29. [PMID: 11863283 DOI: 10.1016/s0378-4347(01)00552-7] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A method for the simultaneous determination of a cyclooxygenase-2 inhibitor, 4-(4-methanesulfonylphenyl)-3-phenyl-5H-furan-2-one (rofecoxib, I) and [13C7]rofecoxib, (II), in human plasma has been developed to support the clinical oral bioavailability (BA) study of I. The method is based on high-performance liquid chromatography (HPLC) with atmospheric pressure chemical ionization tandem mass spectrometric (APCI-MS-MS) detection in the negative ionization mode using a heated nebulizer interface. Two different stable isotope labeled analogs of I were initially evaluated for their use as intravenous (i.v.) markers in the BA study. [13CD3]Rofecoxib was shown to be isotopically unstable in plasma and water containing solvent and an efficient deuterium exchange prevented its use in the study. On the other hand, the isotopic integrity of the subsequently synthesized [13C7]rofecoxib (II) was maintained, as expected, in plasma and other solvent systems. The results of these experiments clearly demonstrated the need for the careful evaluation of the isotopic integrity of the stable isotope labeled compound for the successful utilization of these compounds in BA studies and also as internal standards in the quantitative analysis of drugs in biological fluids. After liquid-liquid extraction of I, II, and internal standard (III) from plasma, the analytes were chromatographed on a narrow bore (100 mm x 3.0 mm) C18 analytical column, with mobile phase consisting of acetonitrile-water (1:1, v/v) at a flow-rate of 0.5 ml/min. The MS-MS detection was performed on a PE Sciex API III Plus tandem mass spectrometer operated in the selected reaction monitoring mode. The precursor-->product ion combinations of m/z 313-->257, 320-->292, and 327-->271 were used to quantify I, II, and III, respectively. The assay was validated in the concentration range of 0.1 to 100 ng/ml of plasma for both I and II. The precision of the assay (expressed as relative standard deviation) was less than 10% at all concentrations within the standard curve range, with adequate assay accuracy. The assay was utilized to support the clinical BA study in which oral doses of I were administered together with an i.v. dose of II to determine the oral BA of rofecoxib at 12.5- and 25-mg doses.
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Rose MJ, Agrawal N, Woolf EJ, Matuszewski BK. Simultaneous determination of unlabeled and carbon-13-labeled etoricoxib, a new cyclooxygenase-2 inhibitor, in human plasma using HPLC-MS/MS. J Pharm Sci 2002; 91:405-16. [PMID: 11835200 DOI: 10.1002/jps.10038] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A method for the simultaneous determination of etoricoxib and its carbon-13 analog ((13)C(6)-etoricoxib) from human plasma has been developed and used to support bioavailability studies. Plasma samples (0.5 mL) were extracted by using a 3M Empore 96-well plate (C(8)) and the resulting extracts were analyzed by using a PE-Sciex API-3000 HPLC-MS/MS with a heated nebulizer interface (500 degrees C). The method was validated with two different calibration curve ranges, one for etoricoxib (5 to 2500 ng/mL) determined in the presence of lower concentrations of (13)C(6)-etoricoxib (0.5 to 250 ng/mL), and a second curve for the quantitation of similar concentrations of both etoricoxib and (13)C(6)-etoricoxib (0.5 to 250 ng/mL). Extraction recoveries of etoricoxib, (13)C(6)-etoricoxib, and a methylated internal standard were >70% over the range of concentrations included in both calibration curves. Intraday precision and accuracy for the quantitation of etoricoxib were 7.8% relative standard deviation (RSD) or less and within 3.4% respectively over the range of 5 to 2500 ng/mL, and 10.8% RSD or less and within 4 % respectively over the range of 0.5 to 250 ng/mL. Within-batch precision and accuracy for the quantitation of (13)C(6)-etoricoxib over the range of 0.5 to 250 ng/mL were 8.3% RSD or less and within 2.3%, respectively. The validated assay was used in support of human clinical trials.
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Affiliation(s)
- M J Rose
- Merck Research Laboratories, Department of Drug Metabolism, West Point, Pennsylvania 19486, USA.
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Zhang H, Henion J. Comparison between liquid chromatography-time of-flight mass spectrometry and selected reaction monitoring liquid chromatography-mass spectrometry for quantitative determination of idoxifene in human plasma. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 2001; 757:151-9. [PMID: 11419740 DOI: 10.1016/s0378-4347(01)00132-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
This study compares HPLC electrospray time-of-flight mass spectrometry and selected reaction monitoring (SRM) LC-MS for high throughput quantitative determination of a small molecule drug in biological samples. A high throughput LC-MS method was developed for quantitatative determination of idoxifene in human plasma and the evaluation was accomplished with the cross-validation of the developed LC-MS method between the time-of-flight mass spectrometer, and a triple quadrupole mass spectrometer operated in the SRM mode. A simple one-step semi-automated 96-well liquid-liquid extraction procedure was used to prepare 96 samples in approximately 30 min and a rapid gradient was used to shorten the LC run time. Time-of-flight mass spectrometry provides acquisition of full-scan mass spectra and extracted ion current chromatograms, which may be extracted from the total ion current chromatogram for peak area determination. The limit of quantitation for idoxifene in human plasma obtained with the time-of-flight mass spectrometer was 5 ng/ml based on 100-microl aliquots of human plasma, and the linear dynamic range was from 5 ng/ml to 2000 ng/ml. The quantitative LC-MS results from the time-of-flight mass spectrometer demonstrated that precision did not exceed 7.1% and accuracy did not exceed 1.7% with reference to quality control samples at three concentration levels in replicates of six. In contrast, the limit of quantitation for idoxifene in human plasma using a tandem triple quadrupole mass spectrometer was 0.5 ng/ml with a linear dynamic range to 1000 ng/ml. The results from the triple quadrupole instrument show that the precision did not exceed 2.2% and accuracy did not exceed 2.9%. The overall results suggest time-of-flight mass spectrometry may be a viable technique for high throughput bioanalytical work for the quantitative determination of a representative small molecule drug in the low ng/ml range in human plasma.
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Affiliation(s)
- H Zhang
- Analytical Toxicology, New York State College of Veterinary Medicine, Cornell University, Ithaca 14850, USA
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Abstract
This review highlights the many roles mass spectrometry plays in the discovery and development of new therapeutics by both the pharmaceutical and the biotechnology industries. Innovations in mass spectrometer source design, improvements to mass accuracy, and implementation of computer-controlled automation have accelerated the purification and characterization of compounds derived from combinatorial libraries, as well as the throughput of pharmacokinetics studies. The use of accelerator mass spectrometry, chemical reaction interface-mass spectrometry and continuous flow-isotope ratio mass spectrometry are promising alternatives for conducting mass balance studies in man. To meet the technical challenges of proteomics, discovery groups in biotechnology companies have led the way to development of instruments with greater sensitivity and mass accuracy (e.g., MALDI-TOF, ESI-Q-TOF, Ion Trap), the miniaturization of separation techniques and ion sources (e.g., capillary HPLC and nanospray), and the utilization of bioinformatics. Affinity-based methods coupled to mass spectrometry are allowing rapid and selective identification of both synthetic and biological molecules. With decreasing instrument cost and size and increasing reliability, mass spectrometers are penetrating both the manufacturing and the quality control arenas. The next generation of technologies to simplify the investigation of the complex fate of novel pharmaceutical entities in vitro and in vivo will be chip-based approaches coupled with mass spectrometry.
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Affiliation(s)
- D I Papac
- Department of Development Research, NPS Pharmaceuticals, Inc., Salt Lake City, Utah 84108, USA
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9
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Gergov M, Robson JN, Duchoslav E, Ojanperä I. Automated liquid chromatographic/tandem mass spectrometric method for screening beta-blocking drugs in urine. JOURNAL OF MASS SPECTROMETRY : JMS 2000; 35:912-918. [PMID: 10934446 DOI: 10.1002/1096-9888(200007)35:7<912::aid-jms19>3.0.co;2-4] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
An automated liquid chromatographic/tandem mass spectrometric (LC/MS/MS) method is presented for the screening and confirmation of 16 beta-blocking drugs in clinical and autopsy urine samples. The described method involved C(18) solid phase extraction, LC separation and MS analysis on a triple-stage quadrupole mass analyser. Samples were initially pre-screened for the presence of any beta-blocking drugs using LC/MS with selected ion monitoring. Any compounds tentatively identified as beta-blocking drugs on the basis of their LC retention time and protonated molecular ion were then automatedly subjected to a second analysis in which the relevant MS/MS product ion mass spectra were acquired. These product ion mass spectra were then automatically searched against a 400-substance mass spectral library containing previously acquired beta-blocking drugs. The results demonstrated that library search of beta-blocking drugs in urine with MS/MS product ion mass spectra was more reliable and produced fewer false negatives than library searching with mass spectra derived from single-stage quadrupole MS. The limits of identification in the MS/MS product ion scan ranged from 0.02 mg l(-1) for carvedilol to 1.2 mg l(-1) for pindolol, the majority of the values being below 0.2 mg l(-1).
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Affiliation(s)
- M Gergov
- Department of Forensic Medicine, University of Helsinki, Finland.
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Zhang H, Heinig K, Henion J. Atmospheric pressure ionization time-of-flight mass spectrometry coupled with fast liquid chromatography for quantitation and accurate mass measurement of five pharmaceutical drugs in human plasma. JOURNAL OF MASS SPECTROMETRY : JMS 2000; 35:423-431. [PMID: 10767773 DOI: 10.1002/(sici)1096-9888(200003)35:3<423::aid-jms953>3.0.co;2-7] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The quantitative determination and accurate mass measurement of five tricyclic amine pharmaceutical drugs (doxepin, desipramine, imipramine, amitriptyline and trimipramine) fortified in human plasma within a per sample run time of 18 s was accomplished by atmospheric pressure ionization (API) time-of-flight (TOF) mass spectrometry using a turboIonspray liquid chromatography/mass spectrometry (LC/MS) interface coupled with high-performance liquid chromatography (HPLC). The relatively short HPLC separation (18 s) was achieved using a short C18 column (15 x 2.1 mm i.d.) with a high aqueous mobile phase maintained at a flow-rate of 1.4 ml min(-1). An acquisition speed of 0.2 s per spectrum accommodates these fast separation conditions. This method employs a one-step liquid-liquid extraction procedure to isolate the five tricyclic amines from biological matrix components The overall extraction recovery was 75% for desipramine and >90% for the other four tricyclic amines. The lower level of quantitation was 1-2 ng ml(-1) for each compound. The calibration curve was linear from 2 to 100 ng ml(-1) for desipramine and from 1 to 50 ng ml(-1) for the other four tricyclic amines. A deuterated internal standard, imipramine-d3, was used for all five tricyclic amines. Acceptable intra- and inter-assay precision (1.0-17.7%) and accuracy (0.2-14.5%) were obtained. The linear dynamic range was extended to 200 based on a software upgrade for correcting ion current detection saturation. The accurate masses of the five tricyclic amines were determined by on-line LC/TOFMS analyses of biological extracts using two-point internal mass calibration. This was done by infusing a reference standard, Jeffamine D230, post-column into the HPLC effluent. All results showed a mass error not greater than 9 ppm for all the target compounds. These results were obtained from both synthetic mixtures when as little as 100 pg were injected or extracts of spiked human plasma samples with analytical concentration as low as 5 ng ml(-1). The factors influencing accurate mass measurements are discussed.
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Affiliation(s)
- H Zhang
- Analytical Toxicology, Cornell University, Ithaca, New York 14850, USA
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