Analytical Instrument Documents

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 performed quantitative analysis of residual agricultural chemicals in carrot extract using a JMS-TQ4000GC.

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 performed quantitative analysis of residual agricultural chemicals in spinach extract using a JMS-TQ4000GC.

Thermogravimetry (TG) is used to measure weight changes of samples under programmed heat conditions. A system combining thermogravimetry/differential thermal analysis (TG/DTA) with mass spectrometry (MS) can be used for both qualitative and quantitative analysis of gases evolved from the TG furnace into the mass spectrometer. In this application note, we show qualitative analysis of the thermal-decomposition process for sodium formate using the “STA2500 Regulus” TG system (NETZSCH) and the gas chromatography–quadrupole mass spectrometry (GC/QMS) “JMS-Q1500GC” system (JEOL).

Silicone rubber is made from low-molecular-weight (LMW) cyclic siloxane. Most LMW cyclic siloxane is used up during the polymerization process, and the residual cyclic siloxane is removed by subsequent heating and depressurization steps. Generally, the residual level of cyclic siloxane is <3% in silicone rubber, but in the field of electronic equipment manufacturing, residual cyclic siloxane levels must be < 1% in order to avoid contact failure of relays, connectors, etc. due to gases evolved by LMW cyclic siloxane. In this application note, we show semi-quantitative analysis results of LMW cyclic siloxane in silicone rubber that was analyzed using the EGA/PY-3030D pyrolyzer (Py) (Frontier Laboratories, Ltd.) and the gas chromatography–quadrupole mass-spectrometer (GC/QMS) instrument JMS-Q1500GC (JEOL).

A thermogravimetry/differential thermal analysis (TG/DTA) system is used to measure weight changes and relative temperatures of samples under programmed heat conditions. A system combining TG/DTA with mass spectrometry (MS) is called a TG-MS system, and is considered one of the best qualitative and quantitative analysis systems for inorganic materials because it can measure sample conditions, evolved gas species, and gas volume simultaneously. In this application note, we introduce the basic application of analyzing calcium oxalate using the TG-MS “STA2500 Regulus” system (NETZSCH) and the GC/QMS “JMS-Q1500GC” system (JEOL).

The phthalates used as plasticizers in polymer resins are endocrine-disrupting substances that are a risk to human health. Therefore, the use of phthalates is limited by various government agencies. In the field of electrical equipment manufacturing, diisobutyl phthalate (DIBP), dibutyl phthalate (DBP), butyl benzyl phthalate (BBP), and di-2-ethylhexyl phthalate (DEHP) are regulated by the European Union’s Restriction of Hazardous Substances (RoHS) Directive. The use of DBP, BBP, DEHP, di-n-octyl phthalate (DNOP), diisononyl phthalate (DINP), and diisodecyl phthalate (DIDP) in toys and baby care products is regulated in Europe, the United States, China, and Japan. Phthalates subject to regulation are being replaced with alternative substances. However, it is known that phthalates tend to contaminate the manufacturing process and storage areas. Some alternative materials (e.g., tris-2-ethylhexyl trimellitate [TOTM]) may contain regulated components (e.g., DEHP) as impurities. In this report, PVC cables for commercial products using alternative substances as plasticizers were analyzed by the pyrolysis/thermal desorption–gas chromatography–mass spectrometry (Py/TD-GC-MS) method described in IEC 62321-8: 2017 [1]. Any phthalates discovered were quantified, and spectral information was collected for other detected compounds.

Electron ionization (EI) is the most commonly used ionization technique in gas chromatography–mass spectrometry (GC-MS). This hard ionization technique (70eV) provides excessive energy to organic compounds that results in highly reproducible fragment ions with relatively high ion intensities. As a result, EI databases have been created that help with identifying the compounds of interest. Despite this ability to do database searches, some compounds (alkanes, alcohols, etc.) do not produce abundant molecular ions, thus making it difficult to differentiate similar compounds from each other. By contrast, photoionization (PI) is a soft ionization technique that uses a vacuum ultraviolet (VUV) light source to provide ionization energies in the range of 8–10eV. This range is optimal for the soft ionization of common organic compounds which have an ionization energy in the range of 8–11eV. This low ionization energy results in stronger molecular ion signals and less fragmentation than for EI. Combining an EI library search with PI molecular ion information can improve the accuracy of the qualitative analysis results. In this work, we report on the qualitative analysis of styrene foam (Styrofoam) before and after photodegradation, using pyrolysis (Py)-GC/MS with an EI/PI combination ion source.

Thermogravimetry (TG) is used to measure weight changes of samples under programmed heat conditions. A system combining thermogravimetry/differential thermal analysis (TG/DTA) with mass spectrometry (MS) is called a TG-MS system, and can be used for both qualitative and quantitative mass spectral analysis of evolved gas from the TG furnace. The TG-MS technique can also be used to analyze the thermal-decomposition process. This application note shows an example of comparative analysis of mechanical-pencil leads of different performances, grades, and manufacturers. These leads are made by baking a mixture of graphite and resin, and then dipping it in oil for hardness and smoothness. Since the resin is carbonized and baked out, the lead is composed of only carbon and oil. In this application note, we show TG-MS analysis results for these mechanical-pencil leads using a “STA2500 Regulus” system (NETZSCH) and a gas chromatography–quadrupole mass spectrometry (GC/QMS) “JMS-Q1500GC” system (JEOL).

The Direct Insertion Probe (DIP) option permits rapid analysis of solid or liquid samples without gas chromatography. Samples contained in a disposable glass capillary are introduced with the DIP directly into the Q1500 ion source through a vacuum lock. The DIP temperature can be programmed for fast or slow heating to desorb or pyrolyze samples for analysis. In this example, we use the DIP to detect additives in a low-density polyethylene storage bag.

Fermenters used for home beer brewing are fitted with an airlock consisting of a liquid barrier that permits the fermentation gases to escape while preventing contamination from atmospheric microbes. Large volumes of carbon dioxide are produced during the most vigorous stages of fermentation, which can occur as early as the first 24 hour period after an ale yeast is added (pitched) to the sweet liquid (wort) produced from barley during the initial mashing step. The gases emitted from the airlock can have a pleasant aroma that can be quite distinctive during the initial stages of fermentation. Solid-phase microextraction (SPME) combined with gas chromatography/mass spectrometry (GC/MS) was used to determine the volatile components contained in the fermentation gas.