Applications in Africa

The suitability of the new cleanup sorbent, Supel QuE Z-Sep+, has been successfully demonstrated for cleanup of beef kidney matrix. It was found to effectively reduce background without significantly reducing recovery of lipophilic pesticides such as organochlorines and some pyrethroids. GC-MS full-scan data indicated Z-Sep+ was found to provide better cleanup in the form of reduced background than PSA/C18, and less interference in the GC-MS/SIM analysis of the target pesticides themselves.

By Merck KGaA, Darmstadt, Germany Office in AFRICA.

The US FDA and international regulatory agencies have set contamination levels for aflatoxins in animal feedstuffs. Since Aspergillus may infect commodities pre-harvest, during storage or during processing, monitoring for aflatoxins in associated agricultural commodities at all stages of production is requisite. Field screening methods exist that are adequate to estimate contamination levels for aflatoxins. When additional confirmation or quantification is desired, chromatographic laboratory analysis is often...

By Merck KGaA, Darmstadt, Germany Office in AFRICA.

The Adsorbent Tube Injector System (ATIS) was developed at Supelco® by R&D Scientists, as a tool to assist in our comprehensive adsorbent research for thermal desorption tubes. The ATIS provides an efficient means of transferring calibration standards in either the gas or liquid phase onto the adsorbent packed tubes. The ATIS employs the technique of flash vaporization to vaporize the sample in a continuous flow of inert gas; the inert gas carries the sample to the tube. The sample pathway of the ATIS is construct...

By Merck KGaA, Darmstadt, Germany Office in AFRICA.

The radiello ammonia sampler impregnated with phosphoric acid represents a low-cost, reliable and simple tool for assessing the atmospheric deposition of ammonia at parts per billion (ppb) concentration levels.

By Merck KGaA, Darmstadt, Germany Office in AFRICA.

QuEChERS (Quick, Easy, Cheap, Effective, Rugged, Safe) is a very popular method for the extraction and cleanup of fruit and vegetable samples for pesticide residue analysis.2-4 The extraction step uses acetonitrile and a salting out effect (with MgSO4). Cleanup is then accomplished using dispersive SPE (dSPE) followed by a centrifuge step prior to analysis. This application shows the clean-up and analysis using Supel™ QuE Z-Sep+ QuEChERS and an SLB®-5ms GC column.

By Merck KGaA, Darmstadt, Germany Office in AFRICA.

When analyzing water and food, trust plays a very important role. Only careful analysis using tests that are performed correctly and are delivering sound results will help to maintain and improve our quality of life. With ready-to-use tests and test systems from Merck Millipore, you can trust your results. Our broad product range covers everything from water analysis to the control of production process up to the measurement of special food parameters.

By Merck KGaA, Darmstadt, Germany Office in AFRICA.

Caramel colorings are used as additives in a broad range of food and beverage products to impart a desired color, but have no nutritional or preservative function. Recently, the potential hazard to humans of ammonia- and ammonia-sulfite-process caramel colorings was raised, because they contain the by-product 4-methylimidazole, which is a potential carcinogen.1 The methylimidazole compounds are difficult to analyze due to their polar nature and low molecular weight. Traditional reversed phase techniques are...

By Merck KGaA, Darmstadt, Germany Office in AFRICA.

Isocyanates are used as a raw material to produce a number of products . Personal exposure can occur while the products made with isocyanates are being applied, or when the materials are removed by grinding or thermal degradation. Workers who are exposed to these compounds are at risk for respiratory disorders and asthma. The highly reactive nature of the isocyanate compounds and the low occupational exposure limits put high demands on both sampling and analytical techniques for monitoring of isocyanates in...

By Merck KGaA, Darmstadt, Germany Office in AFRICA.

An application was developed to demonstrate increased pigment removal for the analysis of pesticides, using Supel™ QuE Z-Sep/C18 QuEChERS and an Ascentis® Express C18 HPLC Column. The improved cleanup can decrease column and instrument fouling, leading to extended LC column lifetime and reduced instrument downtime.

By Merck KGaA, Darmstadt, Germany Office in AFRICA.

Andreas Breidbach [1] and Wolfgang Brodacz [2,3,4] developed a new GC-MS method using fully 13C isotopelabelled analogues of T-2 toxin and HT-2 toxin that allows for the detection of these toxins at concentrations as low as 2–5 ppb.

By Merck KGaA, Darmstadt, Germany Office in AFRICA.

Airborne aldehydes and ketones are collected by passing air through a cartridge containing 2,4-dinitrophenylhydrazine (DNPH). Carbonyl compounds react with the DNPH to form hydrazones, which are immobilized on the cartridge. These compounds can be easily eluted from the cartridge with acetonitrile and analyzed by HPLC with UV detection. Traditionally, this analysis including the workup contains a series of manual steps, which can become time-consuming and could incur experimental error. Automating the extraction...

By Merck KGaA, Darmstadt, Germany Office in AFRICA.

Herbicides are used throughout the world to combat the growth of unwanted plant life. These polar compounds are hydrophilic, so they may find their way into drinking water sources. While gas chromatography has historically been the preferred technique for analysis of herbicides in water samples, the use of LC-MS/MS for this application is gaining acceptance. This is due to the power of MS/MS to provide detailed identification of multiple analytes, but also in part due to the variety of HPLC stationary phases...

By Merck KGaA, Darmstadt, Germany Office in AFRICA.

Beverages, such as sodas and energy drinks, can include a number of polar ingredients, which are easily soluble in the water matrix of the drinks. These ingredients include sweeteners (sugars and sugar substitutes), caffeine, vitamin supplements, amino acids, organic acids, and plant extracts. Because the analytes are already in solution, there is no need for extensive sample preparation. Dilution followed by direct injection into an HPLC is typically suitable. In this article we present two beverage applications...

By Merck KGaA, Darmstadt, Germany Office in AFRICA.