Meeting NJ Low Level TO-15 Air Testing Method Requirements

Author: Jason Herrington

Published By: Restek Corporation

Year of Publication: 2017

Link: http://www.restek.com/Technical-Resources/Technical-Library/Air-Sampling/env_EVAN2708-UNV

Abstract:

The NJ low level TO-15 air testing method is based on U.S. EPA Method TO-15, but it has more some differences that make it quite challenging. The broader calibration range (0.2–40 ppbv) is particularly difficult to meet. In this application note, we focus on the method’s analytical requirements and demonstrate how to meet them using a Markes Unity with CIA Advantage and a 30 m Rtx-VMS column.

Will Pro EZGC Chromatography Modeling Software Work For You? We Put It to the Test!

Published By: Restek Corporation

Year of Publication: 2017

Link: http://www.restek.com/Technical-Resources/Technical-Library/General-Interest/general_GNAR2714-UNV

Abstract:

When it comes to speeding up method development, Pro EZGC modeling software saves you time, materials, and a lot of frustration. This technical article puts Restek’s GC chromatogram simulator to the test and demonstrates how well it predicts actual experimental outcomes.

Instrumentation for Heavy Metals Analysis in Cannabis

Author: Chris English

Restek Corporation

Published By: Cannabis Industry Journal

Year of Publication: 2017

Link: https://www.cannabisindustryjournal.com/column/instrumentation-for-heavy-metals-analysis-in-cannabis/

Abstract:

Heavy metals are common environmental contaminants often resulting from mining operations, industrial waste, automotive emissions, coal fired power plants, amount other sources. Flame Atomic Absorption Spectroscopy (Flame AA) and Graphite Furnace Atomic Absorption Spectroscopy (GFAA) are both techniques that determine both the identity and quantity of specific elements.

Instrumentation Used for Terpene Analysis

Author: Tim Herring

Restek Corporation

Published By: Cannabis Industry Journal

Year of Publication: 2017

Link: https://www.cannabisindustryjournal.com/column/instrumentation-used-for-terpene-analysis/

Abstract:

Because terpenes are somewhat volatile, the Restek team recommends using gas chromatography and advises against using HPLC for terpene analysis.

Many customers ask technical service which instrumentation is best, GC or HPLC, for analysis of terpenes. Terpenes are most amenable to GC, due to their inherent volatility. HPLC is generally not recommended; since terpenes have very low UV or MS sensitivity; the cannabinoids (which are present in percent levels) will often interfere or coelute with many of the terpenes.

New Advice on an Old Topic: Buffers in Reversed-Phase HPLC

Author: Sharon Lupo and Ty Kahler

Published By: LC-GC (chromatographyonline.com)

Year of Publication: 2017

Link: http://www.chromatographyonline.com/new-advice-old-topic-buffers-reversed-phase-hplc

Abstract:

Buffers are commonly used in reversed-phase liquid chromatography (LC) to control the ionization state of analytes. However, the addition of buffers is much more complex than simple pH control. Complex equilibria exist between these mobile-phase additives, the analytes, the silica surface, and even the stationary phase in certain circumstances. The addition of mass spectrometry (MS) as a primary detection technique makes decisions about mobile-phase additives even more crucial. In this column installment, we use a model set of analytes and selected applications to demonstrate the effects that buffers can have not only on the selectivity of a separation, but also on the sensitivity of a reversed-phase analysis when using MS detection.

How to Avoid Common Problems with HILIC Methods

Author: Restek Corporation

Published By: Restek Corporation

Year of Publication: 2017

Link: www.restek.com/Technical-Resources/Technical-Library/General-Interest/general_GNAR2716-UNV

Abstract:

Whether you’ve run HILIC methods before or are attempting to for the first time, there are significant differences between reversed-phase and HILIC methods that must be considered. This article addresses common problems that analysts encounter when running HILIC methods and details how to avoid them and successfully use the technique.

Overcoming the Effects of Highly Organic Protein Precipitation Extracts on LC Peak Shape Using Direct Injection

Author: Sharon Lupo and Frances Carroll

Restek Corporation

Published By: Restek Corporation

Year of Publication: 2017

Link: www.restek.com/Technical-Resources/Technical-Library/Clinical-Forensic-Toxicology/cft_CFAN2667-UNV

Abstract:

Protein precipitation is frequently used to minimize matrix impact when analyzing biological samples. However, the effects of highly organic protein precipitation sample extracts on LC peak shape can negatively impact accurate quantification. Dilution or further sample preparation steps are often used to minimize these effects; however, here we show that direct injection of sample extracts is a viable option that can be used to prevent peak distortion, while avoiding the time and variability associated with additional sample preparation.

High-Throughput Analysis of Immunosuppressive Drugs from Whole Blood by LC-MS/MS

Author: Shun-Hsin Liang and Frances Carroll

Restek Corporation

Published By: Restek Corporation

Year of Publication: 2017

Link: www.restek.com/Technical-Resources/Technical-Library/Clinical-Forensic-Toxicology/cft_CFAN2666-UNV

Abstract:

The success of organ transplant therapy depends in large part on the accurate and timely analysis of immunosuppressive drugs. In this study, we developed a fast, accurate method for the analysis of cyclosporin A, tacrolimus, sirolimus, and everolimus in whole blood. The method pairs a single precipitation step with LC-MS/MS analysis using a Raptor Biphenyl column. A fast, 3-minute analysis time was obtained with no interference from matrix components. Excellent results were obtained for linearity, robustness, accuracy, and precision, demonstrating that the method is suitable for high-throughput therapeutic drug monitoring.

Direct Analysis of Morphine, M3G and M6G Metabolites, and Related Compounds in Urine by LC-MS/MS

Author: Justin Steimling and Frances Carroll

Restek Corporation

Published By: Restek Corporation

Year of Publication: 2017

Link: www.restek.com/Technical-Resources/Technical-Library/Clinical-Forensic-Toxicology/cft_CFAN2665-UNV

Abstract:

The analysis of total morphine is typically conducted by first subjecting urine samples to acid or enzymatic hydrolysis in order to cleave the glucuronide conjugates from morphine’s primary metabolites [morphine-3β-D-glucuronide (M3G) and morphine-6β-D-glucuronide (M6G)] prior to analysis. With the glucuronide moiety removed, the resulting morphine molecule is much less polar and, therefore, more amenable to traditional reversed-phase chromatography. However, both hydrolysis procedures cost an analyst time and result in sample variability due to incomplete hydrolysis or analyte conversion. By utilizing the retention characteristics of the Restek Force Biphenyl column, hydrolysis was not required and direct analysis of morphine, its M3G and M6G metabolites, and several related compounds using a simple “dilute-and-shoot” sample preparation was performed.

Accurate Detection of Residual Solvents in Cannabis Concentrates

Author: Chris English

Restek Corporation

Published By: Cannabis Industry Journal

Year of Publication: 2017

Link: https://www.cannabisindustryjournal.com/category/the-practical-chemist/

Abstract:

Edibles and vape pens are rapidly becoming a sizable portion of the cannabis industry as various methods of consumption popularize beyond just smoking dried flower. These products are produced using cannabis concentrates, which come in the form of oils, waxes, or shatter. Once the cannabinoids and terpenes are removed from the plant material using solvents, the solvent is evaporated leaving behind the product. Extraction solvents are difficult to remove in the low percent range, so the final product is tested to ensure leftover solvents are at safe levels. While carbon dioxide and butane are most commonly used, consumer concern over other more toxic residual solvents has led to regulation of acceptable limits.