|What's New with DART?
The latest developments and news on DART® Mass Spectrometry
With all the fuss about phthalates in the media, we have developed DART methods for rapid screening, and can analyze a few samples for you as well. Just let me know and we'll be happy to put them through our methods.
Additionally a comprehensive review of food fingerprinting was recently published, highlighting the value of DART. And finally, the roundup of the literature has 3 more interesting articles published in the last month.
Please have a look and contact me
if you have any questions or comments. Thanks.
President and CEO
|Are There Phthalates in That Product?|
With the recent health concerns as well as the regulation of phthalates in many products, we examined a variety of them to see how readily DART can identify these. Using both MS/MS as well as high resolution accurate mass, we are able to very rapidly screen for these compounds directly from the consumer product. Below is a table of the targeted materials and their regulatory status
For the isomeric DEHP and DnOP, we needed more structural information in order to differentiate them so we turned to MS/MS. For the analysis, the collision energy was first optimized using an LCQ Deca instrument, ramping through the activation energies of 20, 25, 30, 35, 40, 45%. The DEHP (red) and DnOP (blue) spectra are shown below. The top DART spectra are without additional energy and the bottom with fragmentation. The 260/278 pair clearly differentiates these isomers.
For additional automation we used the DART-SVP with the XZ Scanner on the Thermo Exactive, and placed a piece of "yellow handle" on the scanner. Running the DART at 200C and scanning across the piece gave a positive signal in a few seconds as shown below.
If you have products or materials of concern, please contact us and we will be happy to run a couple samples for you to see if phthalates are present.
|Food Fingerprinting - A Review of Rapid Detection Techniques|
Researchers at the University of Manchester recently published a very nice overview of the various techniques used for detecting the adulteration or contamination of food. They looked at methods where the whole product or material is analyzed directly and a complex fingerprint is obtained, indicating the authenticity (or not) of the material.
They reviewed (with 346 references!) the techniques of vibrational spectroscopy (FTIR, NIR, Ramam), NMR as well as MS techniques (GC/MS. LC/MS/MS, Isotope Ratio MS, ICP-MS) including DART. They pointed out the importance of speed in that "rapid detection and quantification within minutes is highly desirable in order to allow adequate control within HACCP (hazard analysis critical control point) regulated systems." In other words, find the problem before the products are on the stores' shelves.
For DART (with 24 references) they mentioned that it is a "rapidly developing technique that can be used for the target and non-target analysis of complex food matrices. It is seen as a simple and high-throughput system for the qualitative identification of chemical species, metabolomic fingerprinting/profiling and quantification of low-molecular weight food components such as trace organic contaminants.
For details on the paper you can click the title below:
David I. Ellis, Victoria L. Brewster, Warwick B. Dunn, J. William Allwood, Alexander P. Golovanov and Royston Goodacre
|Recent DART Publications|
Detection of nitro-organic and peroxide explosives in latent fingermarks by DART- and SALDI-TOF-mass spectrometry
Frederick Rowella, John Seviourb,Angelina Yimei Limc, Cheryl Grace Elumbaring-Salazarc, Jason Loked, Jan Mae
Fingerprinting Analytics Ltd., 35, Park Road South, Chester le Street, DH3 3LS, United Kingdom, Forensics Ltd., Malvern Hills Science Park, Great Malvern, Worcestershire WR14 3SZ, United Kingdom, Nanofrontier Pte Ltd., Research TechnoPlaza, 50 Nanyang Drive, Singapore 637553, Singapore, Forensic Management Branch, CID, Singapore 088762, Singapore, The School of Materials Science and Engineering, 50 Nanyang Avenue, Nanyang Technological University, Singapore 639798, Singapore
The ability of two mass spectrometric methods, surface-assisted laser desorption/ionization-time of flight-mass spectrometry (SALDI-TOF-MS) and direct analysis in real time (DART-MS), to detect the presence of seven common explosives (six nitro-organic- and one peroxide-type) in spiked latent fingermarks has been examined. It was found that each explosive could be detected with nanogram sensitivity for marks resulting from direct finger contact with a glass probe by DART-MS or onto stainless steel target plates using SALDI-TOF-MS for marks pre-dusted with one type of commercial black magnetic powder. These explosives also could be detected in latent marks lifted from six common surfaces (paper, plastic bag, metal drinks can, wood laminate, adhesive tape and white ceramic tile) whereas no explosive could be detected in equivalent pre-dusted marks on the surface of a commercial lifting tape by the DART-MS method due to high background interference from the tape material. The presence of TNT and Tetryl could be detected in pre-dusted latent fingermarks on a commercial lifting tape for up to 29 days sealed and stored under ambient conditions.
Direct analysis in real time mass spectrometry for the rapid identification of four highly hazardous pesticides in agrochemicals
Yan-Jing Li, Zhen-Zhong Wang, Yu-An Bi, Gang Ding, Long-Sheng Sheng, Jian-Ping Qin, Wei Xiao, Jia-Chun Li, Yong-Xiang Wang, Xue Wang. State Key Lab of New-tech for Chinese Medicine Pharmaceutical Processes, Lianyungang, ChinaJiangsu Kanion Pharmaceutical Co. Ltd., Nanjing, China, State Key Laboratory of Natural Medicines (China Pharmaceutical University), Nanjing, China
RATIONALE The Direct Analysis in Real Time (DART) ionization source coupled with a quadrupole time-of-flight tandem mass spectrometry (Q-TOF MS/MS) system has the capability to desorb analytes directly from samples from complex Chinese herbal preparations without sample cleanup or chromatographic separation.
METHODS In this work, a method based on DART/Q-TOF MS/MS has been developed for rapid determination of geniposide present in 'Re Du Ning Injections', a Chinese herbal preparation. The method has been evaluated for both qualitative and quantitative analysis of geniposide in Re Du Ning Injections.
RESULTS Variables including polarity for ion detection, DART gas heater temperature, matrix effect and sample presentation speed were investigated. The quantitative method was validated with respect to linearity, sensitivity, repeatability, precision and accuracy by using both internal and external standards. A comparison of the results obtained using the DART-based method was made with those obtained using a conventional High-Performance Liquid Chromatography/Diode-Array Detector (HPLC/DAD) by analyzing geniposide in four batches of Re Du Ning Injections.
CONCLUSIONS The DART/Q-TOF MS/MS-based method provides a rapid, efficient and powerful method to analyze compounds from complex Traditional Chinese Medicines with limited sample preparation thus reducing time and complexity of quality control for those materials.
Direct Analysis in Real Time by Mass Spectrometric Technique for Determining the Variation in Metabolite Profiles of Cinnamomum tamala Nees and Eberm Genotypes
Vineeta Singh, Atul Kumar Gupta, S. P. Singh, and Anil Kumar
Department of Molecular Biology & Genetic Engineering, College of Basic Sciences and Humanities, G. B. Pant University of Agriculture and Technology, Uttarakhand, Pantnagar 263145, India, Department of Pharmacology & Toxicology, College of Veterinary Science, G. B. Pant University of Agriculture and Technology, Uttarakhand, Pantnagar 263145, India
Cinnamomum tamala Nees & Eberm. is an important traditional medicinal plant, mentioned in various ancient literatures such as Ayurveda. Several of its medicinal properties have recently been proved. To characterize diversity in terms of metabolite profiles of Cinnamomum tamala Nees and Eberm genotypes, a newly emerging mass spectral ionization technique direct time in real time (DART) is very helpful. The DART ion source has been used to analyze an extremely wide range of phytochemicals present in leaves of Cinnamomum tamala. Ten genotypes were assessed for the presence of different phytochemicals. Phytochemical analysis showed the presence of mainly terpenes and phenols. These constituents vary in the different genotypes of Cinnamomum tamala. Principal component analysis has also been employed to analyze the DART data of these Cinnamomum genotypes. The result shows that the genotype of Cinnamomum tamala could be differentiated using DART MS data. The active components present in Cinnamomum tamala may be contributing significantly to high amount of antioxidant property of leaves and, in turn, conditional effects for diabetic patients.
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|About IonSense |
IonSense, Inc. provides OpenSpot Mass Spectrometry™ solutions to the fields of food safety, forensics, drug development, and chemical analysis. They manufacture and develop direct analysis in real time (DART®) technology licensed from JEOL USA, Inc. and atmospheric solids analysis probe (ASAP™) licensed from M&M Consulting.
DART and ASAP Sources are available for most commercial LC/MS systems. Look here to see if your system is DART-ready. And check here to see if your system is ASAP-ready.