Simplified Methylmalonic Acid Analysis without Derivatization in Human Plasma by LC-MS/MS

Published By: Restek Corporation

Year of Publication: 2018

Link: http://www.restek.com/Technical-Resources/Technical-Library/Clinical-Forensic-Toxicology/cft_CFSS2829-UNV

Abstract: 

Methylmalonic acid analysis is an important clinical test for diagnosing vitamin B12 deficiency as well as methylmalonic acidemia. Methods typically require extensive sample preparation, which involves significant time and expense. The LC-MS/MS method developed here offers a much simpler alternative, providing complete chromatographic resolution of isobaric analytes from the direct injection of a protein crash sample supernatant onto a Force C18 column.

LC-MS/MS Analysis of Urinary Free Cortisol and Cortisone without Matrix Interferences

Published By: Restek Corporation

Year of Publication: 2018

Link: http://www.restek.com/Technical-Resources/Technical-Library/Clinical-Forensic-Toxicology/cft_CFSS2824-UNV

Abstract: 

In general, LC-MS/MS analysis of urinary free cortisol and cortisone can provide better specificity than immunoassay-based methods. However, it is critical that the analytical column has the proper selectivity for chromatographically separating cortisol from isobaric matrix components. In the method presented here, complete separation of the target analytes and matrix interferences was obtained in a 3-minute analysis on a Raptor Biphenyl column.

Simultaneous Analysis of Catecholamines and Metanephrines in Urine by LC-MS/MS

Author: Shun-Hsin Liang and Frances Carroll

Published By: Restek Corporation

Year of Publication: 2017

Link: http://www.restek.com/Technical-Resources/Technical-Library/Clinical-Forensic-Toxicology/cft_CFAN2800-UNV

Abstract: 

Clinical diagnosis of pheochromocytoma and paraganglioma is often based on the analysis of catecholamines (epinephrine, norepinephrine, dopamine) and metanephrines (metanephrine, normetanephrine, 3-methoxytyramine) in urine. Analysis of these polar compounds using reversed-phase LC can be difficult due to limited chromatographic retention, which results in poor separation of the analytes from closely eluting matrix interferences. This method overcomes these problems by combining a simple solid phase extraction procedure with the consistent and accurate chromatographic performance of a Raptor Biphenyl column.

Trace-Level Analysis of Metanephrines in Plasma by HILIC LC-MS/MS

Author: Shun-Hsin Liang and Frances Carroll

Published By: Restek Corporation

Year of Publication: 2017

Link: http://www.restek.com/Technical-Resources/Technical-Library/Clinical-Forensic-Toxicology/cft_CFAN2801-UNV

Abstract: 

Highly sensitive analysis of metanephrines and in plasma is critical in the diagnosis and treatment of pheochromocytoma and paraganglioma. Here, a HILIC LC-MS/MS method was developed using a Raptor HILIC-Si column because this approach provides retention of all target compounds in highly organic mobile phases, thus providing the increased sensitivity needed to reach low detection limits. Data from linearity, accuracy, and precision testing demonstrate that accurate results are consistently obtained—even at trace levels—for these important clinical biomarkers.

Analysis of Fentanyl and Its Analogues in Human Urine by LC-MS/MS

Author: Shun-Hsin Liang and Frances Carroll

Published By: Restek Corporation

Year of Publication: 2017

Link: http://www.restek.com/Technical-Resources/Technical-Library/Clinical-Forensic-Toxicology/cft_CFAN2820-UNV

Abstract: 

Synthetic opioid drugs, such as fentanyl and sufentanil, have very high analgesic potency. Abuse of these prescription painkillers—along with a rapidly growing list of illicit analogues—is a significant public health problem. In this study, we developed a simple dilute-and-shoot method that provides a fast 3.5 minute analysis of fentanyl and related compounds (norfentanyl, acetyl fentanyl, alfentanil, butyryl fentanyl, carfentanil, remifentanil, and sufentanil) in human urine by LC-MS/MS using a Raptor Biphenyl column.

The Effects of LC Particle Choice on Column Performance: Raptor 1.8 µm Superficially Porous Particles (SPP) for UHPLC Analyses

Published By: Restek Corporation

Year of Publication: 2017

Link: www.restek.com/Technical-Resources/Technical-Library/General-Interest/gen_GNAR2803-UNV

Abstract: Superficially porous particles (commonly referred to as SPP or “core-shell” particles) have been proven to provide fast and efficient LC separations. These particles feature a solid, impermeable core enveloped by a thin, porous layer of silica that offers significantly higher efficiency and sensitivity than traditional fully porous particles (FPP). At launch, Raptor SPP LC columns were touted for their selectivity and for their ability to help customers achieve faster separations with their existing HPLC instruments. With the launch of Raptor 1.8 µm columns, this superior Raptor performance has been unleashed on your UHPLC analyses. But, what exactly does that mean? In this technical note, we will explore the benefits of using Raptor 1.8 µm LC columns in your UHPLC instrument with a focus on peak capacity, column lifetime, and selectivity.

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Trace-Level Analysis of Melamine and Related Compounds by LC-MS/MS

Published By: Restek Corporation

Year of Publication: 2017

Link: http://www.restek.com/Technical-Resources/Technical-Library/Foods-Flavors-Fragrances/fff_FFSS2792-UNV

Abstract: The analysis of melamine and related compounds is critical in protecting consumers from adulterated food products. While these highly polar analytes are difficult to retain and accurately quantify on many columns, the Raptor HILIC-Si column and LC-MS/MS method shown here allow quick and complete separations, so melamine and related compounds can be accurately identified and quantified even at residual levels.

LC-MS/MS Analysis of Paraquat and Diquat without Ion-Pairing Reagents

Published By: Restek Corporation

Year of Publication: 2017

Link:http://www.restek.com/Technical-Resources/Technical-Library/Environmental/env_EVSS2791-UNV

Abstract: LC-MS/MS analysis of paraquat and diquat herbicides is an important tool for protecting human and environmental health. However, the ion pairing reagents that are commonly used to improve retention, resolution, and peak shape have a negative impact on sensitivity and can contaminate the system necessitating frequent cleaning. The LC-MS/MS analysis of paraquat and diquat presented here provides complete separation and good peak response for both target analytes in a fast, 7-minute gradient run without the use of troublesome ion pairing reagents.

Highly Selective LC-MS/MS Analysis of Mycotoxins from Multiple Classes

Published By: Restek Corporation

Year of Publication: 2017

Link: http://www.restek.com/Technical-Resources/Technical-Library/Foods-Flavors-Fragrances/fff_FFSS2790-UNV

Abstract: Mycotoxin contamination of crops is not only a public health concern, but it also has a huge impact on the global economy. This highly selective LC-MS/MS analysis of 20 mycotoxins in just 9 minutes allows scientists to accurately identify toxins, to monitor food products for contamination, and to support control strategies that prevent economic loss.

 

Fast, Accurate LC-MS/MS Method for Folate Deficiency Biomarkers in Plasma

Published By: Restek Corporation

Year of Publication: 2017

Link: http://www.restek.com/Technical-Resources/Technical-Library/Clinical-Forensic-Toxicology/cft_CFSS2789-UNV

Abstract:

LC-MS/MS methods for folate deficiency biomarkers in plasma are complicated by the presence of matrix phospholipids and lysophospholipids. These interferences are problematic with reversed-phase LC because they can suppress response, reduce accuracy, and contaminate the MS source. Using a Raptor HILIC-Si column and the HILIC method shown here, folate deficiency biomarkers are completely separated from matrix interferences, allowing accurate determinations to be made in a fast, 5-minute analysis.