MSACL 2018 U.S.

10th Annual Conference & Exhibits of The Association for Mass Spectrometry:
Applications to the Clinical Laboratory, Inc.

Restek at MSACL 2018

BREAKFAST WORKSHOP

Wednesday, January 24
8:00-8:45 / Room 1
A Novel Solution for EtG/EtS Analysis in Human Urine by LC-MS/MS
Presented by Frances Carroll, Restek Corporation
For more information, email Frances Carroll.
Read abstract

Ethyl glucuronide (EtG) and ethyl sulfate (EtS) are unique biomarkers of alcohol use. EtG and EtS analysis offers many advantages for abstinence monitoring including the detection window, stability in stored specimens, and specificity. EtG and EtS are both polar, making them difficult to retain via reversed-phase chromatography. Both compounds are also very sensitive to matrix interferences which can result in being unable to achieve low limits of detection and can also make quantitation impossible. In this study, a simple dilute-and-shoot method was developed and validated for the analysis of EtG and EtS in human urine by LC-MS/MS.


TECHNICAL POSTERS

17D, Wednesday, 10:00
A Novel Solution for EtG/EtS Analysis in Human Urine by LC-MS/MS
Justin Steimling, Shun-Hsin Liang, Landon Wiest, Dan Li, Sharon Lupo, Frances Carroll, Ty Kahler, Sue Steinike, Paul Connolly
Restek Corporation
For more information, email Frances Carroll.
Read abstract

Ethyl glucuronide (EtG) and ethyl sulfate (EtS) are unique biomarkers of alcohol use. EtG and EtS analysis offers many advantages for abstinence monitoring including the detection window, stability in stored specimens, and specificity. EtG and EtS are both polar, making them difficult to retain via reversed-phase chromatography. Both compounds are also very sensitive to matrix interferences which can result in being unable to achieve low limits of detection and can also make quantitation impossible. In this study, a simple dilute-and-shoot method was developed and validated for the analysis of EtG and EtS in human urine by LC-MS/MS.

19D, Wednesday, 10:00
Analysis of Plasma Free Metanephrine, Normetanephrine, and 3-Methoxytyramine by Hydrophilic Interaction Liquid Chromatography
Shun-Hsin Liang, Justin Steimling, Landon Wiest, Sharon Lupo, Frances Carroll, Ty Kahler, Sue Steinike, Paul Connolly
Restek Corporation
For more information, email Frances Carroll.
Read abstract

Metanephrine, normetanephrine, and 3-methoxytyramine are methylated metabolites of epinephrine, norepinephrine, and dopamine, respectively. Measurement of these metabolites in plasma is highly sensitive for the diagnosis of pheochromocytoma and paraganglioma. Analysis of these polar compounds using typical reversed-phase liquid chromatography is difficult due to limited chromatographic retention and lack of sensitivity. As a solution, an LC-MS/MS method was developed based on hydrophilic interaction chromatography using a Raptor HILIC-Si column. Combined with a simple and fast solid-phase extraction procedure, an accurate and precise analysis of plasma free metanephrine, normetanephrine, and 3-methoxytyramine can be achieved and applied to high-throughput clinical assays.

16C, Wednesday, 13:30
Simultaneous Analysis of Catecholamines and Metanephrines in Urine by LC-MS/MS
Shun-Hsin Liang, Justin Steimling, Landon Wiest, Sharon Lupo, Frances Carroll, Ty Kahler, Sue Steinike, Paul Connolly
Restek Corporation
For more information, email Frances Carroll.
Read abstract

Measurements of catecholamines and their methylated metabolites in urine are commonly used for the clinical diagnosis and monitoring of pheochromocytoma and paraganglioma. Although reversed-phase LC-MS/MS has been the method of choice for this type of analysis, challenges still remain for insufficient retention, urine matrix interference, and inconsistent chromatographic performance. To solve these problems, a simple and fast solid-phase extraction (SPE) procedure was developed and followed by LC-MS/MS analysis using a Raptor Biphenyl column.

16B, Wednesday, 13:30
Bile Acid Profiling and Quantification in Human Plasma using LC-MS/MS
Dan Li, Frances Carroll, Ravali Alagandula (presenter), Shun-Hsin Liang, Justin Steimling, Landon Wiest, Susan Steinike, Paul Connolly, Ty Kahler
Restek Corporation
For more information, email Ravali Alagandula.
Read abstract

Bile acids are a group of major catabolic products of cholesterol. They are important biomarkers for signaling potential harmful side effects for new drug development. Quantitation of bile acids in matrices proves to be very challenging due to a number of factors, including, the similarity of structures, varying polarities and stereochemistries, limited fragmentation for unconjugated bile acids in the mass spectrometer, high endogenous levels, and matrix effects caused by phospholipids or triglycerides. In this study, a rapid, robust, selective, and reliable LC-MS/MS method was established and validated in human plasma using a Raptor C18 column with baseline separation of 17 bile acids in 6 minutes.

17C, Thursday, 10:00
Analysis of Urinary Free Cortisol and Cortisone by LC-MS/MS
Sharon Lupo, Frances Carroll (presenter), Shun-Hsin Liang, Justin Steimling, Sue Steinike, Paul Connolly, Ty Kahler
Restek Corporation
For more information, email Frances Carroll.
Read abstract

Determination of urinary free cortisol and cortisone is used to test for various types of adrenocortical dysfunction. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is the preferred screening methodology since it can eliminate interferences that affect immunoassay-based results. Here, a fast and selective 3-minute LC-MS/MS assay is described using a Raptor Biphenyl 2.7 ┬Ám, 50 x 2.1 mm LC column. Linearity, precision, and accuracy were assessed and complete resolution from both endogenous and potential drug interferences was achieved. Samples were extracted using Biotage Isolute SLE+ supported liquid extraction plates to maximize instrument uptime while removing potential data-compromising matrix interferences.

18D, Thursday, 12:30
A Simple Method for the Analysis of Methylmalonic Acid in Human Plasma by LC-MS/MS
Justin Steimling, Ravali Alagandula, Ty Kahler, Frances Carroll
Restek Corporation
For more information, email Frances Carroll.
Read abstract

Vitamin B12 deficiency can manifest itself in a wide variety of physical and behavioral signs and symptoms. A specific marker for diagnosing vitamin B12 deficiency is methylmalonic acid (MMA). In a part of the metabolic cycle for energy production, vitamin B12 promotes the conversion of methylmalonyl CoA to succinyl CoA. If there is not enough B12 available, blood levels of MMA begin to rise. The MMA test typically requires extensive sample pre-treatment incorporating liquid-liquid extraction, derivatization, solvent evaporation, and/or SPE. Additionally, chromatographic resolution can be difficult to achieve between MMA and its naturally occurring isomer, succinic acid. Herein, we present a simple sample preparation method without derivatization which allows for the direct injection of protein crash supernatant while still maintaining resolution in a 5-minute cycle time.


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