Author


Kunihiro Kishida

Latest:

Determining Zeranol in Bovine Tissues Under Nontoxic Conditions

The authors have developed a method of determining zeranol residues in bovine tissues without using toxic chemicals, organic solvents, and reagents in sample preparation and reversed-phase HPLC separation.


Jeffrey S. Rohrer

Latest:

Determination of Hexavalent Chromium Cr(VI) in Drinking Water by Suppressed Conductivity Detection

Development of an ion chromatography (IC) method using suppressed conductivity detection for the determination of Cr(VI) in drinking water.


Pauline Vollmerhaus

Latest:

Challenges in Small-Molecule Quantitation by Mass Spectrometry

Drug discovery scientists are continually striving to improve productivity and efficiency in their workflows. From early discovery to clinical development, existing workflow bottlenecks represent an opportunity to develop solutions to speed the process and improve productivity. The key requirements for quantitative analysis are precision, accuracy, and linear dynamic range. With any quantitative instrument, the hope is that it will be applicable to a vast range of coumpounds, ruggest, and fast. New mass spectrometry (MS) technologies are being developed that meet these criteria and permit high throughput while enabling its application to areas in which speed limitations previously curtailed its practicality. In particular, in the area of ADME profiling, new MS platforms are becoming available that increase the throughput by at least 25-fold, by combining the speed of matrix-assisted laser desorption ionization (MALDI) with the specificity of triple-quadrupole MS. This is bound to greatly accelerate the ADME..


Clarence Wentzel

Latest:

Performance Gains Using Hydrogen Carrier Gas in Refinery Gas Analysis

Escalating costs and increasing demands for helium, coupled with diminishing helium supply, have given rise to the investigation and use of hydrogen as an alternate choice of carrier gas for use in gas chromatography (GC) applications. This application note illustrates that the use of hydrogen as a carrier gas as an alternative to helium in refinery gas applications is not only possible, but also results in improved performance and higher sample throughput.


Stephen J. Valentine

Latest:

Inside the Personalized Medicine Toolbox: GCxGC-Mass Spectrometry for High-Throughput Profiling...

The authors present results that suggest that high-throughput, high-coverage profiling capabilities, such as those afforded by GCxGC-TOF-MS, can impact the development of personalized medicine.


Scott Silver

Latest:

Analysis of Hydrophilic Molecules in Biological Fluid with Novel Mixed-Mode Column

In pharmaceutical development, it is important to analyze small molecules or their metabolites in biological fluids. For this purpose, the analytical methods such as sample pretreatment, 2D-LC and LC–MS have been developed. However there are still problems of resolution and protein adsorption. As a result, satisfying analytical results have not always been achieved.


César R. Silva

Latest:

Enhanced Stability Stationary Phases for HPLC

This article presents an overview of high performance liquid chromatography stationary phases with enhanced stability at high pH, focusing on the methods by which they were prepared. Among the many alternatives, the authors introduce reversed phases based upon metallized silica supports that show superior performance during stability testing at high pH, when compared with conventional C18 phases based upon bare silica.


O.J. Pozo

Latest:

Detection of Doping Agents by LC–MS and LC–MS-MS

In the last decade, research on the detection of all groups of doping agents has been investigated by LC-MS, and routine LC-MS screening applications are now available for almost all classes of doping agents.


Polymicro Technologies, A subsidiary of Molex Incorporated

Latest:

Brittleback in Polyimide Coated Capillary Tubing

Polyimide coated fused silica capillary tubing is widely used in the separation sciences. In some instances a condition called brittleback can appear in the tubing. Its causes and remedies are discussed.


Shiseido Co., Ltd.

Latest:

Increased Resolution and Reproducibility with TSKgel® UP-SW3000 Columns Versus a Competitive Column

TSKgel UP-SW3000 columns are 2 µm SEC columns designed for the analysis of monoclonal antibodies and other biopharma products. Higher resolution can be achieved for the separation of antibody monomers, dimers, and higher order aggregates with a TSKgel UP-SW3000 column compared to a competitor UHPLC column. The TSKgel UP-SW3000 column provided excellent reproducibility for the peak parameters of retention time, asymmetry, and column efficiency. As demonstrated by the %RSD values, injection-to-injection reproducibility was superior to the competitor column.


Jerry Zweigenbaum

Latest:

Analysis of 122 Veterinary Drugs in Meat Using All Ions MS-MS with an Agilent 1290/6545 UHPLC–QTOF System

A 12-minute analytical method was developed for 122 VDs in meat. The method uses Agilent All Ions MS/MS on a Q-TOF LC/MS instrument along with the Agilent Veterinary Drugs PCDL.


Diab Elmashni

Latest:

Mass Detection for Chromatographers

Liquid chromatography coupled with mass spectrometry (LC–MS) is one of the most powerful analytical tools for organic compound analysis.


Friedhelm Gores

Latest:

Molar Mass Determination of Collagen Peptides

Hydrolyzed collagens (collagen peptides) are water-soluble products obtained by hydrolysis of natural proteins and used for dietary supplements. A simple GPC/SEC method is described for molar mass determination of collagen peptides, allowing reliable molar mass determination using ultraviolet (UV) detection.


Dr. Bingwen Yan

Latest:

Multi-Mode Water Soluble Vitamin Separation Using ZirChrom®-SAX

Traditionally the analysis of water-soluble vitamins by reversed-phase HPLC has been complicated by the lack of retention for these compounds on conventional silica C18 columns. Here we demonstrate efficient, multi-mode, baseline resolution of six water-soluble vitamins in 6 min using a ZirChrom®-SAX column.



Edgar D. Lee

Latest:

Analysis of Organic Compounds in Water Using Unique Concentration–Injection Techniques for Portable GC–MS

In this study, a simple method was used for extraction and concentration of trace organic compounds in water, followed by injection using a coiled wire filament and GC–MS analysis. Common semivolatile organic compound contaminants at low parts-per-billion levels were detected in less than 10 min.


Nicholas Santiago

Latest:

Simultaneous Measurement of an API with its Counter-ion Using Corona CAD with HPLC-HILIC

The analysis of anions and cations is critical during drug development and related QC. Measure both the API and the counterion in a single run.


Thomas D. McClure

Latest:

Study of Free Radical Fragment Ions Generated from ESI-CID-MS-MS Using LTQ and LTQ Orbitrap Mass Spectrometers

Studies of odd-electron CID behaviors reveal that free radical fragmentation is structure-dependent and is directly correlated with the functional groups that stabilize the newly-formed free radicals.


Krispin Stoob

Latest:

Online Automated SPE–LC–MS-MS Quantitation of Sulfonamide Antibiotics and Pesticides in Surface Waters Using a Triple-Quadrupole Mass Spectrometer and Electrospray Ionization Probe

This article describes a fully automated online solid-phase extraction–liquid chromatography–tandem mass spectrometry (SPE–LC–MS-MS) setup using a mass spectrometer and an electrospray ionization probe for analyzing different groups of polar contaminants in natural waters. The goal was to develop an online SPE method for the quantification of sulfonamide antibiotics, including their acetyl metabolites, as well as for frequently used pesticides (triketones, phenylureas, chloracetanilides, phenoxyacetic acids, amides, and triazines) in ambient waters. The analytical methods were applied successfully for a field study in an agricultural region within the catchment area of Lake Greifensee near Zurich, Switzerland.


Mark Emanuele

Latest:

Charged Aerosol Detection in Pharmaceutical Analysis: An Overview

Over the past several years, charged aerosol detection (CAD) has become a widely used technology in the pharmaceutical laboratory. From formulation to stability and even quality control, many analysts are turning to this technology due to its advantages of sensitivity, ease of use, dynamic range, and applicability to a wide range of analyses in the drug development process. In this article, we will examine the operation and use of CAD in a regulated environment, briefly address method development and validation specifics, and highlight a few examples illustrating some of its advantages when used in the pharmaceutical laboratory.


Lee Davidowski

Latest:

A Comparison of ICP-OES and ICP-MS for the Determination of Metals in Food

The determination of inorganic elements in food substances is critical for assessing nutritional composition and identifying food contamination sources. The inorganic elements of interest can be divided into two classes: nutritional and toxic. It is important to determine the levels of both sets of elements accurately to assess both the nutritional and the harmful impacts of food substances. Nutritional elements such as Mg, P, and Fe are present at high levels (milligrams per kilogram), while toxic elements such as Pb, Hg, and Cd should be present only at trace levels (nanograms or micrograms per kilogram).


David M. Goodall

Latest:

Elevated Temperature HPLC: Principles and Applications to Small Molecules and Biomolecules

The effects of temperature on HPLC are explored, along with a critical analysis of the effects of temperature change on both peak shape and efficiency.


Jingzhong Xu

Latest:

LC–MS-MS Determination of Malachite Green and Leucomalachite Green in Fish Products

Although not currently used in U.S. or European aquaculture, malachite green (MG) is still an effective and inexpensive fungicide that is used in other countries, particularly in Asia. During metabolism, MG reduces to leucomalachite green (LMG) (Figure 1), which has been shown to accumulate in fatty fish tissues. Trace levels of MG and LMG residues continue to be found in fish products. In a 2005 report, MG was found in 18 out of 27 live eel or eel products imported from China to Hong Kong local market and food outlets, resulting in a government recall and destruction of all remaining products (1).


Karel A.J. Snoble

Latest:

Stability of Formic Acid in Methanol Solutions and the Implications for Use in LC–MS Gradient Elution Analysis

Dilute formic acid solutions in methanol were found to decline in acid content with time, the extent of the decline depending upon the initial amount of water present in these solutions. The effect of the formic acid concentration change upon the separation of peptides using high performance liquid chromatography (HPLC) is examined briefly.


Henrik T. Rasmussen

Latest:

Use of Orthogonal Methods During Pharmaceutical Development: Case Studies

The primary goal of early phase development is to gain a fundamental knowledge of the chemistry of drug substances and drug products to facilitate optimization of synthetic schemes and drug product formulations. At the same time, methods are required for release and stability studies to support clinical trials. Ultimately, the knowledge gained during early development translates into designing control methods for commercial supplies. Our approach to meeting this challenge is based upon the use of a primary method along with orthogonal methods. This paper will discuss the overall strategy, with an emphasis on the chromatographic conditions selected to provide systematic othogonality for a broad range of drugs. Case studies will be presented to demonstrate the utility of orthogonal methods to resolve issues that could not have been addressed using a single release and stability method.



Michael J. Telepchak

Latest:

Determination of Cannabinoid Content and Pesticide Residues in Cannabis Edibles and Beverages

As a result of the rapid growth of the cannabis industry, many testing laboratories are looking for efficient, reliable, and cost-effective analytical methods to analyze chemical residues, such as pesticides, mycotoxins, solvent residues, terpenes, and heavy metals, as well as cannabinoid concentration in cannabis-infused edibles and beverages. In this article, QuEChERS (quick, easy, cheap, effective, rugged, and safe), a sample preparation technique widely adopted in the food testing industry, is introduced to the discipline of forensic testing as a viable method for the extraction of pesticides and cannabinoids in various complex sample matrices. The claimed amounts of cannabinoids versus the actual amounts are compared, as well as the pesticide residue levels in edible and beverage samples.


Amber Awad

Latest:

Validation of LC–MS-MS Methods for the Determination of Ibuprofen in Miniature Swine Plasma and Synovial Fluid

Published methods for the determination of ibuprofen in biological fluids by liquid chromatography (LC)–UV or LC–mass spectrometry (MS)-MS have quantitation ranges consistent with the relatively high but typical ibuprofen dose (200–800 mg), generally having lower limits of quantitation in the low micrograms-per-milliliter range. For the analysis of plasma and synovial fluid samples from preclinical (miniature swine) studies utilizing a novel ibuprofen dosage form, LC–MS-MS methods were developed and validated over the 10–1000 ng/mL range. Ibuprofen undergoes biotransformation to ibuprofen acyl glucuronide and sublimes under routine bioanalytical sample handling conditions. Procedures were implemented to minimize the impact of these potential liabilities.


Chen Jing

Latest:

Faster, More Sensitive Determination of Carbamates in Drinking Water

U.S. EPA Method 531.2 describes the determination of widely used carbamate pesticides in raw surface water using HPLC with fluorescence detection following postcolumn derivatization, which enhances method sensitivity and selectivity as compared to UV absorbance detection.