Mark S. Anderson
Analytical Chemistry and Materials Research Group, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
Spacecraft contamination was analyzed using mass spectrometry with the direct analysis in real-time ionization source. This source uses metastable helium for soft ionization and to mediate atmospheric desorption of samples into a mass spectrometer. The sampling methodology allows polymers to be assessed for the presence of vacuum labile components. Vacuum labile residues are significant sources of contamination on spacecraft optics, science instruments, and thermal control surfaces. The methodology also provides sensitive analysis of molecular contamination on spacecraft surfaces using existing spacecraft sampling procedures. This provides identification information for a wide range of molecular components including biomarker compounds.
Xiaowei Wang, Jingfu Liu, Charles C. Liu, Jing Zhang, Bing Shao, Liping Liua, Nina Zhanga
Beijing Key Laboratory of Diagnostic and Traceability Technologies for Food Poisoning, Beijing Center for Disease Control and Prevention, Beijing, China, State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, China,
ASPEC Technologies Limited, Beijing, ChinaTrimethyl phosphate (TMP) is used extensively in industrial chemical processes. Due to the high polarity and volatility, methods for its quantification in environmental samples have not been well developed. Currently, the pollution status of TMP in the environment still have not been quantitative analyzed. This study quantifies the TMP levels in environmental water via direct analysis real-time ionization source interfaced with a triple quadrupole mass spectrometer (DART-MS/MS) with multiple reaction monitoring (MRM). The DART parameters were optimized to achieve the most TMP-sensitive MRM responses. The water samples were analyzed directly, and an isotope-labeled internal standard (ISTD) method was applied for quantification. The method exhibits significant linearity (R > 0.998) in the range of 0.05-100 ng/mL, with a limit of quantification (LOQ) of 50 pg/mL. TMP has been accurately detected in the influent and effluent water of two municipal wastewater treatment plants and a river located in Beijing. Recovery of TMP ranged 88.0-107.6% for the spiked real water samples. The results demonstrated that TMP has been existed in environmental water, and DART-MS/MS can be used for the monitoring of the pollution status and the environmental process of TMP in environmental water
Edgard O. Espinoza, Cady A. Lancaster, Natasha M. Kreitals, Masataka Hata, Robert B. Cody, Robert A. Blanchette
U.S. National Fish and Wildlife Forensics Laboratory, Ashland, OR, USA, Centre for Forensic Science, University of Western Australia, Perth, Western Australia, Australia, Shoyeido Incense Company, Kyoto, Japan, JEOL USA, Inc., Peabody, MA, USA, Department of Plant Pathology, University of Minnesota, St. Paul, MN, USA
RATIONALE It is important for the enforcement of the CITES treaty to determine whether agarwood (a resinous wood produced in Aquilaria and Gyrinops species) seen in trade is from a plantation that was cultivated for sustainable production or was harvested from natural forests which is usually done illegally.
METHODs We analyzed wood directly using Direct Analysis in Real Time (DART™) ionization coupled with Time-of-Flight Mass Spectrometry (TOFMS). Agarwood was obtained from five countries, and the collection contained over 150 samples. The spectra contained ions from agarwood-specific 5,6,7,8-tetrahydro-2-(2-phenylethyl)chromones as well as many other ions. The data was analyzed using either kernel discriminant analysis or kernel principal component analysis. Probability estimates of origin (wild vs cultivated) were assigned to unknown agarwood samples.
RESULTS Analysis of the DART-TOFMS data shows that many of the chromones found in cultivated and wild agarwood samples are similar; however, there is a significant difference in particular chromones that can be used for differentiation. In certain instances, the analysis of these chromones also allows inferences to be made as to the country of origin. Mass Mountaineer™ software provides an estimate of the accuracy of the discriminate model, and an unknown sample can be classified as cultivated or wild. Eleven of the thirteen validation samples (85%) were correctly assigned to either cultivated or wild harvested for their respective geographic provenance. The accuracy of each classification can be estimated by probabilities based on Z scores.
CONCLUSIONS The direct analysis of wood for the diagnostic chromones using DART-TOFMS followed by discriminant analysis is sufficiently robust to differentiate wild from cultivated agarwood and provides strong inference for the origin of the agarwood.
twelve sample positions can be loaded automatically or manually, including standards for quantitation. QuickStrips are available in packages of 50 permitting 600 measurements per box.