Related Articles

• High Mass Resolution MALDI-Imaging MS: High Stability of Peak Position during Imaging MS Measurement

  Matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-Imaging MS) is a powerful tool for the biochemical analyses of surfaces. Previously, this technique has been used to determine the spatial distribution of hundreds of unknown compounds in thinly sliced tissue sections. The mass spectral images are generated by changing the laser irradiation point at regular intervals across the sample surface and collecting a mass spectrum for each point. Time-of-flight mass spectrometers (TOFMS) are widely used as the mass analyzer for MALDI-Imaging MS because they are well matched for the MALDI ionization process. However, the fine structure of the matrix crystals and small irregularities in the tissue surface flatness can cause peak drift in the collected mass spectra that is caused by slight differences in the starting point of the flight path for the ions at each laser irradiation point. As a result, the typical reflectron type TOFMS systems have a difficult time achieving high mass resolution from spot to spot over a thinly sliced biological surface. Conversely, the JEOL JMS-S3000 “SpiralTOFTM”, which has 5-10 times longer flight path than the reflectron type TOF, is able to reduce the effect of this mass drift to achieve high mass resolution and high mass accuracy. In this work, we report the advantages of using the SpiralTOF for MALDI-Imaging MS analyses of lipids in a mouse brain tissue section.
• Sudan Dyes Analysis by AccuTOFTM LC/MS System

  Sudan dyes are red dyes that are used for coloring solvents, oils, waxes, petrol, and shoe and floor polishes. They are considered to be carcinogens and teratogens. Due to this fact, the US and the EU do not permit the use of these colors as food additives. However, in some countries, these dyes are still occasionally used in order to intensify the color of bell pepper and chili powders. Here, we describe a simple LC/TOF-MS method for sudan dyes I, II, III, and IV analysis.
• The Blue Lotus Flower (Nymphea caerulea) Resin Used in a New Type of Electronic Cigarette, the Re-Buildable Dripping Atomizer

  The blue lotus flower (Nymphea caerulea) is an Egyptian water lily containing apomorphine and nuciferine. Apomorphine has been described as a psychoactive alkaloid and is a non-selective dopamine agonist primarily used to treat Parkinson’s disease as it stimulates dopamine receptors and improves motor function. Nuciferine is an alkaloid associated with dopamine receptor blockade. Today, blue lotus flower is used as a sleep aid and anxiety reliever. The rebuildable dripping atomizer (RDA) is an electronic cigarette that allows direct application of an e-liquid onto the coil in the atomizer for aerosolization, compared to a typical electronic cigarette where the e-liquid is wicked from a storage vessel to the coil. Our laboratory received a dark-brown resin material from a concerned parent. The resin had been confiscated from an adolescent who had a reported history of marijuana use. The resin was later identified as blue lotus flower (N. caerulea). This resin, together with four commercially available blue lotus products, was analyzed for content. Apomorphine was detected in two samples, and nuciferine was detected in all five samples. The confiscated resin was determined to contain no apomorphine and 4300 ng/g of nuciferine. The nuciferine resin was shown to aerosolize using aRDA electric cigarette.
• New Generation LC-TOF/MS “AccuTOFTM”

  It has been a decade since Dodonov and his colleagues [1] first announced the electrospray ionization time-of-flight mass spectrometer (ESI-TOF MS). Their initial findings have been enhanced by Standing and others [2,][ 3], and it has been recently reported that a large TOF MS system achieved a mass resolution exceeding 10,000 [4]. Encouraged by the results acquired by Dodonov and Standing, some of the MS manufactures have produced bench top ESI-TOF MS systems. However, most of these commercial models have a narrow dynamic range and are unfit to quantitative analysis because they use a TDC (Time-to-Digital Converter) as a data acquisition system. Their applications were mainly in qualitative analysis with exact mass measurement, and are limited in such fields as environmental studies and chemical dynamics that require only qualitative analysis. Because of detector saturation, these systems only show good mass acuracy when operated within a limited analyte concentration range.
• Stability in quantitative analysis of residual agricultural chemicals in food by GC-MS/MS - MSTips262

  As "food safety" is recognized as an increasingly important issue on a global scale, many nations have their own regulations on residual agricultural chemicals in food. In Japan, the positive list system, which was enforced at the end of May 2006, stipulates a uniform standard of 10 ppb as a quantity that is considered safe for human health. Under the positive list system, more agricultural chemicals need to be examined, and as a result, techniques capable of accurately and collectively analyzing residual agricultural chemicals in food are in increasing demand. While mass spectrometry (MS) is known for its high detection sensitivity, MS/MS is becoming the mainstream of pesticide analysis for its superior sensitivity and selectivity. The JMS-TQ4000GC, JEOL’s latest GC-MS/MS, has a unique ion storage/ejection mechanism within the MS/MS collision cell and incorporates new firmware to support MS/MS analysis with up to 36,000 transitions. In this work, we report the stability of 8 pesticides that were added to spinach extract.
• DART Contamination Resistance: Analysis of Compounds in Saturated Salt and Buffer Solutions

  DART provides very simple mass spectra that are free of multiple charging and alkali metal cation adducts such as [M+Na]+  and [M+K]. This facilitates identification of target compounds in mixtures and simplifies assignment of elemental compositions for unknowns.