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JEOL Resources

Documentation in support of your JEOL product.

Rapid Detection of Melamine in Dry Milk Using AccuTOF-DART

Recent events have led to the recall of both pet food and dairy food products from international consumer markets. In both cases, melamine was added to these products to show a higher chemical signature for proteins, which in turn would increase the reported quality of the food. Unfortunately, the effect of this melamine addition caused the death of both pets and babies that consumed these tainted products. As a result, there is growing government and consumer concern towards the presence of melamine in food products. Because of this concern, there is a need for a rapid and accurate test to quickly determine the presence of melamine in these food products. Previously, the JEOL AccuTOF-DART was shown to be an effective technique for determining the presence of melamine in pet food. In this work, we extend the application of AccuTOF-DART to show that melamine can be rapidly detected when it is present in dry nonfat milk.

Rapid Detection of Fungicide in Orange Peel

Thiabendazole is an anthelmintic and a highly persistent systematic benzimidazole fungicide that is widely used for controlling spoilage in citrus fruit. It is considered a General Use Pesticide (GUP) in EPA Toxicity Class III – Slight Toxicity. A small piece of orange peel (a few square millimeters in size) from a Florida orange was placed in the DART sampling region. Compounds present in the peel were detected within seconds. Among these were the familiar orange-oil flavor components such as limonene and sinensal as well as polymethoxylated flavones that are attributed with antioxidant and cholesterol-reducing properties.

Rapid Detection and Exact Mass Measurements of Trace Components in an Herbicide

Analytical chemists are often asked to identify trace components in manufactured compounds such as drugs, consumer products, and agricultural chemicals. A common approach to the identification of minor components is to use gas or liquid chromatography coupled with high-resolution mass spectrometry. Although this approach is effective, it may be time consuming and difficult to set up. The AccuTOF with Direct Analysis in Real Time (DART™) provides a rapid solution. The high dynamic range of both source and detector permit the determination of minor components in the presence of a major component. The AccuTOF always provides high resolution data with exact mass measurements and accurate isotope ratios that can provide elemental composition assignments for unknown compounds.

Rapid Analysis of p-Phenylenediamine Antioxidants in Rubber

p-Phenylenediamine (PPD) and derivative compounds are commonly used as antioxidants and antiozonants in black rubber. These compounds can cause sensitization leading to contact dermatitis in susceptible individuals. Detection of additives in polymers such as rubber can be important for clinical, forensic, and manufacturing applications. Here we show that DART can be used to identify the presence of these compounds within seconds without requiring any solvents or sample preparation.

Rapid Analysis of Glues, Cements, and Resins

DART™ can be used to analyze polymers, cements, resins, and glues by increasing the gas temperature to 450-550°C to induce pyrolysis. This has been applied to a variety of glues and resins, including epoxies, polyimide resins, PVD cement, and cyanoacrylates. Examples are shown here for cured and uncured epoxy resin and cyanoacrylate glues. The DART was operated with helium in positive-ion mode. The gas heater was set to 475°C. Resins were cured in an oven for several hours before analysis; some resin samples had been cured for longer periods of time (months or years). Exact masses and accurate isotopic abundances were used to assign elemental compositions for peaks in the mass spectra. Nominal-mass spectra were exported into a library database in NIST format to facilitate identification of unknowns.

PaperSpray® Accessory for AccuTOF™-LP and AccuTOF™-DART® Systems

Samples and a polar solvent such as methanol are deposited onto a porous substrate such as filter paper or chromatography paper cut into a triangle. When a high voltage (typically ~3000V) is applied, Electrospray Ionization (ESI) occurs at the tip of the paper triangle. PaperSpray is simpler than ESI and does not require a pump, spray needle, desolvating gas or precise alignment.

“No-prep” Analysis of Lipids in Cooking Oils and Detection of Adulterated Olive Oil

Dietary fats are categorized according to the level of unsaturation. Oils are a mixture of triglycerides and free fatty acids. Olive oil contains a high concentration of monounsaturated fatty acids, while other oils such as Canola and safflower oil contain larger amounts of polyunsaturated fatty acids. Characterizing the type of lipids present is important for quality control and for detecting adulteration of more expensive oils (e.g. olive oil) with cheaper products. Analysis by HPLC is time consuming and requires solvents and consumables. DART provides a convenient alternative: no solvents are required and the analysis can be completed in seconds.

“Laundry Detective”: Identification of a Stain

The AccuTOF-DART™ was recently applied to an unusual analytical problem: finding the cause of oily stains on freshly laundered shirts (Figure 1). No cutting or extraction was required. Stained and unstained regions of the shirt were placed in the DART gas stream and the mass spectra were acquired.  The DART parameters were: helium gas, flow 3-4 LPM, gas heater set to 175 degrees C, positive-ion mode, PEG 600 exact mass reference standard. These conditions did not damage the shirt.

Instantaneous Screening for Counterfeit Drugs with No Sample Preparation

Drug counterfeiting is becoming a serious and widespread public health problem. The number of FDA open investigations into drug counterfeiting rose sharply from 2000 to 2001 and has remained high in recent years. Counterfeit drugs are not only illegal, but dangerous; they may contain little or no actual drug content, or they may contain completely different drugs with potentially toxic consequences. The problem is worldwide; it has been reported that nearly 50% of all anti-malarial drugs in Africa are thought to be counterfeit. Direct Analysis in Real Time (DART™) offers a simple solution to screening for counterfeit drugs. DART can detect the presence or absence of drugs in medicines within seconds by simply placing the pill or medicine in front of the mass spectrometer. In combination with the AccuTOF, DART provides exact masses and accurate isotopic patterns that provide elemental compositions for known and unknown substances.

Instantaneous Detection of the “Date-Rape” Drug -- GHB

Gamma hydroxybutyrate (GHB) is a fast-acting central nervous system depressant. Prior to its ban by the FDA in 1990, GHB was sold in bodybuilding formulas. It has been abused as a euphoriant. Because it is colorless and odorless, it can be added to alcoholic drinks of unsuspecting victims. An overdose can result in serious consequences, including respiratory depression and coma. GHB was classified as a Schedule I Controlled Substance in March, 2000. Detection of GHB is problematic. GC/MS and LC/ MS methods are time consuming. A rapid colorimetric assay for GHB has been developed, but this assay suffers from some limitations. For example, ethanol produces the same colorimetric response as GHB. The AccuTOF™ mass spectrometer equipped with Direct Analysis in Real Time (DART™) can rapidly detect GHB anion (C4H7O3 -, m/z 103.0395) on surfaces, in urine, and in ethanol. No solvent extraction, wipes, or chromatography are required. Examples are shown in the figures below.

Analytical Instruments Documents

Other Resources

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Media

Corona - Glow Discharge (DART Ion Source)

February 22, 2020
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