What is DART?
Direct analysis in real-time (DART) is a mass spectrometry technique that uses an ion source to analyze samples of molecules via the interaction of the ions with the molecules.
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DART has become established in numerous industries due to its versatility, simplicity, and speed in analyzing a wide variety of samples.
Solids, liquids, and gases can be investigated by DART, which can take place in ambient environments, obtaining precise mass measurements of the samples.
Fields such as; drug control, environmental research, food, forensics, fragrance, pharmacology, quality control, security, and others, have adopted the DART technique into various applications to explore a wide range of substances both as whole items and as traces on surfaces.
Developing DART for drug screening applications
The DART technique has been beneficial for drug screening. Recent years have seen the increasing need for effective and rapid screening techniques that can reliably analyze and detect the increasing number of illegal drugs currently in circulation.
There has been increasing workload demand in analytical laboratories, leading to the development of improved analytical techniques to assess a broad range of samples.
In the late 2000s, DART was explored for applicability to drug screening techniques. DART had previously been demonstrated as a reliable technique for identifying a variety of substances, from the metabolites of pharmaceuticals to toxins and explosives.
One of the first studies to explore the potential of DART in drug screening investigated the effectiveness of DART in screening forensic evidence for illicit drugs.
The study established a lower detection limit in DART, demonstrating effectiveness at screening for solid dosage forms of controlled substances which led to the Virginia Department of Forensic Science incorporating DART.
A more recent study analyzed the effectiveness of combining DART with a chromatographic technique to develop a system of rapidly screening for drugs.
The study investigated the success of DART in screening for known drug standards, as well as for analyzing samples of unknown drug concentrations that had been confiscated from a UK music festival.
The results showed that DART was able to recognize the known drug samples, as well as being able to identify the unknown samples.
Numerous studies have investigated the use of DART in combination with time-of-flight (TOF) mass spectrometry.
The results of combining the two techniques were that drug screening accuracy was improved, the workflow was reduced, as were cycle times and reduced process time as there is no requirement for sample preparation. Overall, the combined technique was concluded to enhance laboratory productivity and accuracy in results.
A further study comparing the effectiveness of DART paired with TOF against other firmly established drug screening techniques such as thin-layer chromatography, color tests, and ultraviolet spectroscopy demonstrated that the previously established techniques were useful for categorizing samples, however, DART combined with TOF was highly specific in identification of the substance.
DART is a useful method for enhancing drug screening techniques, increasing accuracy, reducing testing time, with the capability of assessing and identifying a range of substances. The use of the technique is predicted to be utilized by forensic labs and law enforcement for rapid, on the spot screening of substances.
- Cody, R. B., Laramée, J. A., & Durst, H. D. (2005). Versatile new ion source for the analysis of materials in open air under ambient conditions. Analytical Chemistry, 77(8), 2297-2302.
- Lian, R., Wu, Z., Lv, X., Rao, Y., Li, H., Li, J., Wang, R., Ni, C. and Zhang, Y. (2017). Rapid screening of abused drugs by direct analysis in real-time (DART) coupled to time-of-flight mass spectrometry (TOF-MS) combined with ion mobility spectrometry (IMS). Forensic Science International, 279, pp.268-280.
- National Research Council. (2009). Strengthening forensic science in the United States: a path forward. National Academies Press.
- Steiner, R. R. (2018). Use of DART-TOF-MS for screening drugs of abuse. Analysis of drugs of abuse (pp. 59-68). Humana Press, New York, NY.
- Steiner, R. and Larson, R. (2009). Validation of the Direct Analysis in Real-Time Source for Use in Forensic Drug Screening. Journal of Forensic Sciences, 54(3), pp.617-622.