Applications from Sigma-Aldrich | Environmental XPRT

Improved Reproducibility and Reduced Sample Preparation Time for the HPLC Analysis of Aflatoxins in Raw Peanut Paste

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...

radiello™ Passive Sampler as a Tool for the Measurement of Atmospheric Ammonia Concentrations and Dry Deposition

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.

Evolution of Three Decades of Separations Research

Analysis of Isocyanates Using the ASSET™ EZ4-NCO Dry Sampler

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...

Formaldehyde and Acetaldehyde Determination in Air Using Fully Automated On-Line Desorption and Analysis of DNPH Cartridges

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...

Capabilities of the Adsorbent Tube Injector System (ATIS™)

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...

Determination of Additives in Beverages using Ascentis Express Columns

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 application...

Analysis of Pesticides in Beef Kidney

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.

Increased Pigment Removal with Analysis of Pesticides in Oranges

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.

A New GC-MS Method for Mycotoxin Analysis Using 13C-marked Mycotoxin Derivatives

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.