The Application Notebook September 2016

September 2016 | Volume , Issue 5
Analyzing a broad range of semivolatile environmental pollutants at low levels requires a sensitive detector as well as an inert sample pathway. While semivolatiles analysis by methods such as EPA 8270 and EPA 625 typically does not require reporting sub nanogram-on-column concentrations, the latest generation of sensitive mass spectrometers and inert GC columns and inlet liners allow analysts to take advantage of the benefits of split injection while maintaining standard method reporting limits.
This study describes a simple, quick approach for the sampling and analysis of nicotine, impurities, and flavour compounds in e-cigarette vapours. Combining thermal desorption (TD) with gas chromatography–mass spectrometry (GC–MS) analysis results in a versatile screening method for tackling the challenge of regulatory compliance and quality control in this rapidly expanding industry.
The rising numbers of liquid chromatography–mass spectrometry (LC–MS)-based metabolomics applications and untargeted metabolism studies have increased the need for reliable chromatographic separations for a large quantity of molecules with widespread polarities.
Antibody related biopharmaceuticals represent one of the most dynamic segments of the pharmaceutical market. The analysis and monitoring of product titers in CHO cell cultures is one of the key tasks during development of new products. Cell line selection, optimization of expression rates, and process control need fast and efficient antibody quantification. Besides ELISA assays with known limitations with regard to reproducibility and precision, high performance liquid chromatography (HPLC) analysis using affinity chromatography is applied. This application note summarizes some performance data of a new Protein A affinity column for mAb titer analysis.
Pharmaceutical/Drug Discovery
There has been a significant resurgence in the development of antibody-drug conjugates (ADC) as target-directed therapeutic agents for cancer treatment. Among the factors critical to effective ADC design is the Drug Antibody Ratio (DAR). The DAR describes the degree of drug addition that directly impacts both potency and potential toxicity of the therapeutic, and can have significant effects on properties such as stability and aggregation. Determination of DAR is, therefore, of critical importance in the development of novel ADC therapeutics.
Whole column imaging detection capillary isoelectric focusing (iCIEF) has been recognized as a powerful tool for biopharmaceutical development and quality control. Unlike conventional single point detection capillary electrophoresis (CE) systems, in which light absorbance or emission at a specific point along the separation capillary is monitored, iCIEF detects a line of light that is passed through and radiates from the entire separation capillary. As a result, sequential snapshots of the whole separation capillary at different times are obtained. This allows sample separation and interaction in real time to be observed during electrophoresis, enabling fast analytical method development, high resolution separation, and high sample throughput.
This application note describes the transfer of a conventional LC method for the analysis of antihistaminic drugs from an Agilent 1100 Series Quaternary LC to an Agilent 1260 Infinity II LC, and demonstrates that equivalent results can be obtained.
Proteins — especially monoclonal antibodies (MABs) — have become increasingly important in pharmaceutical work. However, there are some important differences between conventional, chemically-synthesized drugs and proteins. Because of the complex and weak structure of proteins, even a slight change in conditions, such as pH value, temperature, or mechanical stress, may lead to aggregation and a loss of activity or stability.
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