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Five simple pictures that reveal problems with your GC analysis – and how to fix them!

The German Beer Purity Law of 1516 makes beer one of the best analyzed food products with the highest standards regarding quality, freshness, appearance, and flavor. According to this law, beer is allowed to contain hops, malt, yeast, and water as ingredients. Of course, beer also contains major B vitamins, bitter substances, and minerals and trace elements (such as Ca, Na, Mg, and Zn) that are important for human nutrition. However, undesirable substances such as pesticides and heavy metals (for instance Cd, Pb, Hg, Sb, and As) can be found as well, mostly as contaminants in brewing water and grains. In particular, the herbicide glyphosate has to be monitored carefully since it is discussed as a possible carcinogenic. The chromatography of glyphosate is challenging because of its high polarity. A well-established method including a derivatization step with 9-fluorenylmethyl chloroformate (FMOC) followed by LC–MS analysis is time-consuming and also susceptible to errors. A sample pretreatment without derivatization is desirable because it is faster and cheaper. A triple quadrupole mass spectrometer optimizes the analytical procedure and establishes a routine method for the analysis of glyphosate in beer. For the determination of low element concentrations, such as As, Se, Pb, Cd, and Zn, inductively coupled plasma-mass spectrometry (ICP-MS) is applied.

The quantitative extraction and subsequent purification of trace contaminants from (semi-)solid environmental and food matrices of regular size (that is, a few grams) is still recognized as a challenging task, typically accomplished through relatively complex off-line multistep treatment procedures. When these conventional sample preparation procedures are applied to the treatment of size-limited samples (of less than 1 g), the difficulties increase. This review discusses the different analytical strategies that can be adopted to overcome (or at least reduce) these difficulties when chromatographic techniques are involved for final instrumental determination.

Interfering peaks or high baseline background can compromise the results of gradient liquid chromatography (LC) separations.

Many gas chromatographers are not fully aware of safe practices for handling high-pressure gas cylinders. Gas chromatography (GC) operators should be trained to properly transport, install, connect, and maintain their gas supplies, as well as to deal with emergencies. In the first of a two-part series, this month’s “GC Connections” examines the principal hazards and safety issues surrounding the compressed gas cylinder. Next month’s instalment will present safe procedures for routine cylinder use.

Cartenoid compounds can be used as probes for studying bonded stationary phases for reversed-phase liquid chromatography, such as C18, phenyl-hexyl, and cholesteryl. From one supercritical fluid chromatography (SFC) analysis that favours the chromatographic behaviours related to the stationary phase properties, bonding density, ligand type (monomeric or polymeric), and endcapping treatment, two separation factors are calculated allowing us to build a two-dimensional map. These two axes are related either to the shape selectivity or the polar surface activity (residual silanols). Each point on the map corresponds to a column. The retention factor of β-carotene, which describes the phase hydrophobicity, is indicated by the size of the point. More than 200 stationary phases were studied, including small particle sizes and superficially porous ones.

Lab Innovations, the UK’s only event dedicated to laboratory professionals, will be held from 2–3 November 2016, at the National Exhibition Centre (NEC) in Birmingham, UK. It will feature an extensive conference programme and highlight a wealth of industry suppliers.

Significant benefits can be obtained by standardizing high performance liquid chromatography (HPLC) columns in a pharmaceutical development laboratory. Here is a story of how one organization attempted to encourage its staff to develop HPLC methods using fewer column brands and dimensions to reduce waste and efforts in method transfers downstream.

An introduction from the guest editors of this special supplement from LCGC Europe revealing recent developments in small-molecule drug analysis.

The first high performance liquid chromatography (HPLC) column for enantioselective chromatography was introduced commercially in 1981. This chromatographic mode has now become the method of choice for the analysis of chiral pharmaceutical compounds, making previous approaches, such as optical rotation, almost completely obsolete. However, supercritical fluid chromatography (SFC) has been gaining increasing recognition as a complementary technique to HPLC for pharmaceutical enantioselective analysis. Gas chromatography (GC) and capillary electrophoresis (CE) remain very useful for particular applications.

The proportion of counterfeit medicines has increased dramatically. Combatting this issue is complex, and various levels of action are necessary. The quality control (QC) of imported batches using simple, reliable, and cost-efficient analytical approaches is vital. Capillary electrophoresis (CE) is becoming important because the analysis is achieved in a capillary with small dimensions, and is usually filled with an aqueous buffer. No organic solvent is required and injection volumes are in the nanolitre range, which is convenient because of the low availability of reference substances and reduces the environmental impact. CE is now recognized by numerous Pharmacopeia and can be used for counterfeit and substandard characterization as a validated analytical procedure that adheres to international guidelines.

This application note details a GC-MS-based analytical method for the qualitative and quantitative determination of Irganox 1076 and 1010 in polyethylene.

Click the title above to open the LCGC Europe October 2016 regular issue, Vol 29, No 10, in an interactive PDF format.

Click the title above to open the LCGC Europe October 2016 Advances in Pharmaceutical Analysis Supplement, Vol 29, No s10, in an interactive PDF format.

Click the title above to open the LCGC North America October 2016 regular issue, Vol 34 No 10, in an interactive PDF format.

Click the title above to open the October 2016 issue of Current Trends in Mass Spectrometry, Volume 14, Number 4, in an interactive PDF format.

The quantitative extraction and subsequent purification of trace contaminants from (semi-)solid environmental and food matrices of regular size (that is, a few grams) is still recognized as a challenging task, typically accomplished through relatively complex off-line multistep treatment procedures. When these conventional sample preparation procedures are applied to the treatment of size-limited samples (of less than 1 g), the difficulties increase. This review discusses the different analytical strategies that can be adopted to overcome (or at least reduce) these difficulties when chromatographic techniques are involved for final instrumental determination.

Brian Rohrback, PhD, president of Infometrix Inc., in Bothell Washington, will receive the International Society of Automation’s (ISA) Excellence in Analytical Technical Innovation Award.

The ban on organotins has not led to a significant reduction in marine pollution according to research published by the Polish Academy of Sciences. Researchers found unacceptable levels of harmful organotins in the muscle and liver tissues of fish species collected in the Southern Baltic Sea coastal zone exceeding the good environmental status boundaries.

What are the problem-solving skills required to succeed in analytical chemistry?

Carbon tetrachloride (CCl4) is a potent greenhouse gas in the troposphere, while in the stratosphere it contributes to ozone destruction. Global atmospheric models treat anthropogenic industrial processes as the sole source of atmospheric CCl4. However, some evidence suggests that biogenic sources may also contribute. This article describes grab-sampling with analysis by thermal desorption–gas chromatography–mass spectrometry (TD–GC–MS) to assess levels of CCl4 in a Central Amazonian rainforest. We find that ambient air mixing ratios within and above the forest, while agreeing with current equatorial estimates (120 ppt), show diurnal and canopy-height variations that suggest a biogenic source of CCl4, and therefore may be important for closing the gaps in the global atmospheric CCl4 budget.

Biotage AB has announced the purchase of shares in the Danish biomolecule company Chreto Aps, representing a significant investment into the area of drug development.

What are the motivations and events that drive a successful separation scientist? This is the question that CASSS seeks to answer by documenting the lives and careers of the analytical chemists who have won their “Outstanding Achievements in Separation Science” Award.

Click the title above to open The Column September 21, 2016 Europe & Asia issue, Volume 12, Number 17, in an interactive PDF format.

Click the title above to open The Column September 21, 2016 North American issue, Volume 12, Number 17, in an interactive PDF format.