Innovative mass spectrometric solutions
HDX Automation Systems
Stable Isotope Labeled Chemical Reagents
Enzyme columns for HDX MS
Small Molecule Bioanalysis
Small Molecule Quantification
Drug & Metabolites Quantification
Quantitation using Sciex API5000 Triple quadrupole mass spectrometers
Quantitation using Thermo TSQ Quantiva Triple quadrupole mass spectrometer
Quantitation or quantitative & qualitative analysis using Thermo Q Exactive hybrid quadrupole-Orbitrap mass spectrometer
Chemical synthesis quality control using UPLC-UV-HRMS
Small Molecule Biomarker Assays
Innovative and reliable UPLC-MRM MS assays
Development of robust, sensitive, accurate, high throughput LC-MS/MS assays for quantitative measurement of small molecule biomarkers in different biological matrices remains an analytical challenge. This could be due to the biomarker instability, low basal levels in biological matrices, poor ionization, poor retention on reverse phase columns, etc. We offer extensive knowledge and expertise in developing and implementing innovative and reliable LC-MS/MS assays for a variety of small molecule biomarkers using hyphenated techniques, e.g., increased sensitivity using chemical derivatization, increased throughput using UPLC etc.
Figure 1 : Reductive ethylation labeling of DA, NE and E with d(4)-acetaldhyde.
Figure 2. Representative chromatograms of basal levels of DA, E and NE in mouse plasma.
We have the following UPLC-MRM MS biomarker assays for bioanalyses of the corresponding small molecule biomarkers in different biological matrices:
Simultaneous measurement of dopamine (DA), epinephrine (E), norepinephrine (NE), serotonin (5-HT) and normetanephrine (NM) in CSF and microdialysate samples
Simultaneous determination of dopamine (DA), epinephrine (E), norepinephrine (NE) in mouse, rat, monkey, and human plasma
Quantification of acetylcholine (ACH), Histamine (HA), 1-methylhistamine (MHA), and 1-methyl-4-imidazoleacetic acid (MIAA) in rat, monkey, and human CSF
Quantification of 11,12- and 14,15-epoxyeicosatrienoic acids (EETs) and dihydroxyeicosatrienoic acids (DHETs) in rat plasma and urine
Determination of glutamate and aspartate in rat CSF, microdialysates, and brain tissue
Chengjie Ji, Wenlin Li, Xiao-dan Ren, Ayman F El-Kattan, Rouba Kozak, Scott Fountain and Christopher Lepsy “Diethylation Labeling Combined with UPLC/MS/MS for Simultaneous Determination of a Panel of Monoamine Neurotransmitters in Rat Prefrontal Cortex Microdialysates” Anal. Chem. 2008, 80, 9298–9309.
Chengjie Ji, Justin Walton, Yi Su and Max Tella, “Simultaneous Determination of Plasma Epinephrine and Norepinephrine Using an Integrated Strategy of a Fully Automated Protein Precipitation Technique, Reductive Ethylation Labeling and UPLC-MS/MS”, Analytica Chimica Acta 2010, 670, 84-91
G. Zhang, Y. Zhang, C. Ji, T. McDonald, J. Walton, E.A. Groeber, R.C. Steenwyk, and Z. Lin, Ultra sensitive measurement of endogenous epinephrine and norepinephrine in human plasma by semi-automated SPE-LC-MS/MS. J. Chromatogr. B Analyt. Technol. Biomed. Life Sci. 2012, 895-896 186-90.
Drug Metabolite Identification and Profiling
Whole blood or plasma stability test
Microsomal and hepatocyte stability evaluation
Enzymatic reaction phenotyping
Protein binding evaluation using ultracentrifugation or RED (rapid equilibrium dialysis)
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