A Precise Review on Applications and Basic Concept of Direct Analysis in Real Time Mass Spectrometry (DART-MS)

Shivani Sharma, Navdeep Singh*, Amar Deep Ankalgi, Arti Rana, Mahendra Singh Ashawat

Laureate Institute of Pharmacy, Kathog, Jawalamukhi, Himachal Pradesh 176031, India.

*Corresponding Author E-mail: navdeepsingh23.ns@gmail.com

ABSTRACT:

Direct real time analysis (DART) is the most successful tool for the analysis of the compounds. This technique is useful for the identification, and classification of compounds. It is widely followed by the forensic chemistry, and also used for many purposes. Their main applications include inks, paints, drugs, bank dyes, explosives, beverages, and gunshot etc. The basic concepts of DART-MS were highlighted to understand the process. Also the basic fundamentals of DART-MS including special function were discussed. Various natural products were discovered by DART-MS includes plant tissue, insects, and microbe etc. The main focus of this review article is on the applications of direct real time analysis, which covers the varieties of uses in our pharmaceutical as well as chemical industries. This technique was helpful in the production of food material, and to identify the contaminants from animal sources in the part of veterinary drugs. Also, used in food processing in the form of additives, and adulterants. DART-MS has huge applications on analysis of seized drug like steroids supplements, psychoactive plants etc. Also, in inks, paint, and documents industry this technique has been widely used. So, this review covers the basic fundamentals of direct real time analysis DART-MS, and their applications.

KEYWORDS: DART-MS, Concept of direct analysis in real time, discovery of natural products, and applications.

INTRODUCTION:

A decade has passed since the introduction of direct sampling and atmospheric pressure ionization for mass spectral analysis. Since then, a plethora of methods have been available in this particular field of mass spectrometry (MS), often referred to as ambient MS or ambient desorption / ionization (ADI)¹. 

The key feature of environmental EM is that individual compounds and mixtures, as well as objects, can be subjected to mass spectral analysis with no or at least minimal pretreatment, i.e. generally (almost) no sample preparation required for environmental Member States². Direct real-time analysis (DART) was published in early 2005 as the second environmental EM technique, shortly after the introduction of desorption electrospray ionization (DESI) in late 2004.Today, despite the multiple competing MS techniques that have increased (and decreased) since then, DESI and DART are the most established methods out of a total of more than 40 related methods³. To date, work related to DART-MS, basic research and multiple analytical applications, has resulted in approximately 400 publications with an annual output of 60-70 research articles in the years 2012-2014.

These advances include the use of solid phase extraction (SPE) to simplify complex mixture analysis, high-temperature thermal desorption to unlock detection of low-volatility compounds and confined thermal desorption for repeatable and safe analyses. Implementation of advanced mass spectrometers as well as ion or differential mobility spectrometry preceding MS detection has allowed for additional dimensionality to the data which can increase confidence in the results⁴. Additionally, the adoption of statistical or chemometric approaches for data analysis have shown the viability of DART-MS to be used for classification of samples, whether that be cocaine attribution, ignitable liquid classification, or timber species identification. In few fields has the use of DART-MS been so widely demonstrated as in forensic chemistry. Analysis of nearly all types of evidence has been demonstrated, including drugs, explosives, gunshot residues, ignitable liquid residues, inks, paints, polymers, lubricants, bank dyes, beverages, and insects. This review does not intend to reiterate the content of the past review articles, but instead supplement them by providing insight into the recent (2015 to present) advances of the technique for forensic chemistry⁵. This review is organized by the main focus of applications in the literature. To provide greater context for those who may be less familiar with DART-MS, a brief discussion on the fundamentals of the technique, alternate approaches to sample analysis, and commonly employed chemometric tools are included. A summary of additional resources relevant to forensic chemists is also provided along with the perceived research needs and discussion of the potential future of the technique⁶.

BASIC DART-SETUP AND CONCEPT:

Primary ionization source:

The entire DART source includes a closed ion source (or primary ion source) and a reaction zone that extends from its outlet through the open atmosphere to the sample (surface). At the ion source, helium is guided through an anaxially segmented tube. In the first compartment, a corona discharge between a needle electrode and a first perforated disk electrode produces excited ions, electrons and atoms Figure 1⁷.

The electrical discharge inside the DART ion source can be classified as a corona glow discharge (C - G), operating at discharge currents of the order of 2 mA and a gas temperature of only 50-60°C. The cold plasma passes through a second chamber where the cations are removed from the gas stream by passing it through another perforated electrode. The gas stream is then variably heated by an auxiliary heating element and guided through a third grid electrode to remove anions and electrons. Therefore, the helium gas leaving the ion source in the atmospheric reaction zone contains only electronically excited neutral species⁸. The sectional view of Figure 1 shows the first commercial version of the DART ion source. Although changes have been made to the design of the current model (DART-SVP), the principle has been maintained⁹.

Reaction zone and interface:

The ion source provides electronically excited helium atoms which, upon emission from this unit, will immediately ionize the surrounding gas (laboratory atmosphere) and eventually analyze the material. The source of the primary ionizing species can be adjusted to a variety of angles and distances¹⁰. Generally, a distance of 5 to 25mm is established between the gas outlet and the API interface port to introduce the sample into the ionization zone. Although the primary ionizing species are helium atoms, the ionization of the analyte molecules is mainly carried out by secondary ions created in the surrounding air, that is, by the reactants. The ions of the analyte are thus formed by chemical ionization processes at atmospheric pressure and finally transferred to the mass analyzer¹¹.

DART-MS ionization mechanism:

Inside the DART ion source, an electrical discharge is applied to the helium gas, generating plasma (Figure 1). Cations, anions and electrons are removed with grid electrodes leaving neutral metastable species electronically excited at the source exit¹². The samples are placed in ambient conditions in the area between the ion source and the mass spectrometer inlet, a space that can be adjusted between 5 and 25 mm.

Figure 1: Schematic diagram of DART-MS

DART MS is best suited for the analysis of small molecules below m/z 1500. The temperature of the helium flow is adjustable from 50 to 550°C, a parameter that can be useful for improving the thermal desorption of polar and heavier molecules¹³.

Evaporation before gas-phase ionization:

In DART-MS, samples are subjected to gas phase ionization processes closely related to those effective in atmospheric pressure chemical ionization (APCI) or atmospheric pressure photoionization (APPI). As already mentioned, excited helium atoms, when released into the atmosphere, initiate a cascade of reactions in the gas phase. This results in reactive ions created by atmospheric water vapor or other gaseous compounds present¹⁴. The function of the helium gas adjustable cylindrical heating is to provide the energy for this process. Fortunately, the concentration of analyte molecules in the phase gas must be high and there is no need to produce an extended "cloud". In some circumstances, for example, the rapid evaporation of thermally stable salts, thermal desorption alone can provide ions in the gas phase, e.g. by separating the charges in the gaseous phase. This is exploited in atmospheric pressure thermal desorption ionization (APTDI)¹⁵.

Fundamentals, alternative approaches to sample analysis and chemometric techniques:

Fundamentals of DART-MS:

The fundamental process behind DART-MS is the use of heated metastable gas atoms to desorb and ionize a compound or material of interest. The creation of metastable gas atoms is achieved by generating a plasma, using a high voltage needle, to create charged and metastable species. The charged species are neutralized by an electrode inside the source, resulting in a flow of metastable atoms, which are heated before exiting. A final grid electrode is located at the output of the DART source and is used to prevent ion-ion recombination. Figure 1 presents a crosssectional view of the DART ion source¹⁶. It is believed that the ionization mechanism, for the positive ionization mode, is driven by the ionization of water in the atmosphere equation-1, which generates clusters of charged water equations 2 and  which subsequently ionize the sample (equation (4)) [3].    

He* +H₂O → He + H2O⁺ + e⁻                                          [1]

H₂O⁺ +H₂O → H₃O⁺ + OH^∙                                              [2]

H₃O⁺ + _nH₂O → [(H₂O) _n+1 + H]⁺                                   [3]

M⁺ [(H₂O)_n+1 +H]⁺→ [M+H]⁺ + (H₂O)_n+1                       [4]

Other gas sources, such as nitrogen, argon and air have been demonstrated with varying degrees of success. These gases do not have metastable atoms with enough energy to directly ionize water. Direct ionization of the analyte, or do pant, is required, and therefore the ionization of the analyte is typically less efficient equation 5, and 6. Furthermore, the use of air as a source gas can lead to the generation of ozone which has a detrimental effect on the source hardware¹⁷.

N* 2 +M→N₂ +M^+∙ +e⁻                                                     [5]

M^+⋅ + M → [M− H]^⋅ + [M + H]⁺                                      [6]

Specialized functions of DART MS:

Ionization has several distinctive characteristics suitable for the analysis of natural products. First, the outdoor setup allows for direct analysis of various types of samples, including liquids, gases, living tissue, clothing, paper, thin layer chromatography (TLC) plates and insect carcasses 7) (Fig. 1). The chemical profile that is generated represents natural products as they are in the context of the natural biological matrix. The minimal setup greatly reduces run time, reduces material loss and reduces artifacts from lengthy extraction and purification processes¹⁸.

In addition, the sampling configuration allows for easy introduction of chemical do pants into the DART helium stream. For example, the vapors of trifluoroacetic acid or ammonia placed in the ionization zone increase the ionization of explosives1) and triacylglycerols respectively. The coupling of a direct ozone flow with the DART ionization generates ozonolysis products from unsaturated fatty acids, allowing discerning the position of the carbon carbon double bond¹⁹. In contrast, the analysis of natural products using conventional approaches of La gas chromatography (GC) or liquid chromatography (LC) requires multiple preparatory steps including extraction, chromatographic separation, combination, concentration and derivatization. Extensive processing may require significant amounts of starting material to compensate for sample loss.

Also, degradation, oxidation and other artifacts can occur during sample preparation. A second distinctive advantage of DART MS is that the polar and heavier molecules often missed by GCMS can be detected by DART MS. Finally, the near instantaneous profile of DART MS allows for monitoring of chemical reactions or changes in the chemical profile of living organisms at multiple time points10-12 at multiple time points²⁰.

As with any analytical technique, DART ionization has several inherent limitations. First, fragmentation can occur at higher plasma temperatures, making it difficult to interpret spectra and accurately determine the mass of intact molecules. However, for some samples, this characteristic can be informative because the information. The structural structure can be inferred from the m/z of the decay fragments (see the next section on plant tissue). A second limitation of DART ionization is that the analytes are subject to oxidation artifacts, an event that depends on the distance from the capillary outlet²¹. Finally, saturated hydrocarbons can undergo hydride extraction. In this scenario, the aliphatic hydrocarbon signals, detected as [M - H]⁺, are indistinguishable from the signals corresponding to monounsaturated hydrocarbons of the same carbon length (detected as [M + H]⁺) which makes it difficult quantitative analysis. 

A second method such as GCMS or deuterium exchange is needed to distinguish between the two compounds. Therefore, the integration of DART MS with other analytical methods is essential, especially when measuring natural uncharacterized products for the first time. Despite these drawbacks, DART MS is a powerful analytical method for the targeted analysis of small molecules of natural substrates and for chemical fingerprinting, an application that compares the general pattern of signals generated by an analyte and does not require the identification of individual components. Below, it provide recent applications of DART MS for the analysis of plants, animals, microbes and metabolites of living tissues and biological fluids²².

DART Classification:

In this source of atmospheric pressure, metastable argon atoms are created by a discharge from the needle-disc electrode. The excited argon atoms then collide with a resistively heated pin coated with the sample, where they ionize. Atmospheric Sampling Glow Discharge Ionization (ASGDI) uses a reduced pressure glow discharge. The vapor sample is introduced into the exhaust, i.e., ASGDI requires volatile samples and cannot directly desorb material from surfaces²³. The metastable source of the atomic bombing (MAB) of Bertrand et al is based on the Penning ionization in vacuum. More recently, Penning atmospheric pressure (APPeI) ion source was developed by the Hira oka group. APPeI uses corona discharge from needle electrodes in an argon atmosphere to deliver metastable ions and is only suitable for volatile samples. Indeed, there are similarities between the gaseous phase ionization mechanisms that lead to analyte ions, as they share some of the reaction types that lead to ion formation. However, differences arise because the ionization conditions are different from one method to another²⁴.

DISCOVERY OF NATURAL PRODUCTS BY DIRECT ANALYSIS IN REAL-TIME MASS SPECTROMETRY:

Plant Tissue:

Chemotaxonomy from lipids, alkaloids and saccharides Species identification of organisms is most commonly performed using morphological features and / or DNA barcodes. Another method of species identification, chemotaxonomy, and uses the chemical profiles of biological markers, such as metabolites or surface molecules, as a chemical fingerprint. The chemical profiling performed by DART MS is nearly instantaneous, requires little or no sample preparation, and can provide preliminary structural identities of biomarkers, particularly when combined with tandem MS.

Figure 2: Examples of some natural chemical products of plants, insects, and microbes which are detected by DART-MS²⁷

Profiling of plant mixtures:

Even the analysis of complex plant mixtures is possible using DART MS. The chemical footprint of propolis, a natural health supplement made from wax, bee saliva, and resinous plant exudates, revealed a number of signals corresponding to glycosides and phenolics, among other small molecules. Using linear discriminant analysis, the chemical profiles of propolis samples from various locations can be distinguished from each other²⁵.

Insects:

Direct analysis of cuticular lipids:

The cuticular surfaces of insects are rich in lipids, amino acids and other small molecules Figure 2. Some of these compounds function as pheromones, olfactory or gustatory signals that are sent and received by members of the same species and influence social behaviors such as mate seeking, spawning and kinship recognition. Isolation, structural characterization and functional characterization of the samples. Insect pheromones have been areas of intense research in the field of natural product chemistry due to their importance for chemical ecology and their application to pest control. DART MS has been increasingly used for insect classification and pheromone characterization due to its rapid analysis time and wider mass range²⁶.

APPLICATION OF DART-MS:

DART-MS applications for food safety:

Methods of Sample Preparation:

DART-MS is one of the most versatile analysis tools with good compatibility to meet various detection needs for food safety and quality assurance, as it doesn't just work with them²⁸.

Simple or absent methods of preparation:

Since DART allows direct sample injection, little or no preparation is required. Therefore, DART-MS has proven to be an ideal time and effective strategy. Some low viscosity liquid samples, for example beverages, and solid samples, for example, tea can be used for direct analysis²⁹. Regarding VOC analysis, a cDART ion source allows direct detection of the injured onion. Due to some pesticide residues distributed on the fruit surface, it is possible to obtain a direct analysis of the fruit peel with tweezers³⁰.

Methods of preparation of logged samples:

To determine dissolved or suspended analytes in liquid samples, solid phase extraction (SPE) is used for purification and/or isolation by selective adsorption with solid adsorbents on a column (or cartridge). The SPEs are divided into normal phase SPE, reverse phase SPE, ion exchange SPE. Various solvents, for example acetonitrile, n-hexane, n-hexane/dichloromethane (3:1, v/v), hexane/diethyl ether (96:4, v/v), and acetone/n-hexane (3:1, v/v) were used in the polarity of analytes³¹.

A. Food Production:

Contaminants from raw materials of plant origin: pesticide residues:

Pesticides (eg, fungicides, insecticides, and herbicides) are substances used to protect crops from exogenous organisms³². In recent decades, pesticide residues and their metabolites have become one of the most serious problems that greatly affect the safety of plant-based raw materials, because excessive levels can have serious negative effects on human health and alter the balance of the ecosystem. The first application for pesticide residues with DARTTOF-MS was submitted by the Hajslova group³³.

Contaminants from raw materials of animal origin: residues of veterinary drugs:

Foods of animal origin are an important category of the human diet (especially in Western countries)³⁴. Today, the use of veterinary drugs is essential to prevent disease and protect animal health. However, veterinary drug abuse can cause serious residual chemical risks to public health, so efficient scrutiny by potential tools such as DART-MS is in great demand. analyzed in real time. Most of the target benzimidazoles were ionized in positive DART ionization mode, while ionization of some benzimidazoles and coccidiostats was achieved in negative mode. Common parameters such as gas temperature and specific resolutions (1,000, 2,500, 5,000 and 10,000 FWHM respectively) were studied in detail³⁵.

Analysis of food raw materials: food component and its traceability and genuineness:

The food component is a fundamental category of food raw materials for the characterization of safety. In general, according to whether it is dangerous for human health, food components can be classified into three sub-categories: beneficial, as a functional component; questionable, such as caffeine and phytohormones; harmful, like natural toxin. In general, the fact that food components are present or comply with regulatory requirements has a great influence on the safety, quality, traceability and genuineness of food³⁵.

B. Food processing:

Contaminants expected: food additives and adulterants:

With the advent of processed foods, many food additives of both natural and artificial origin have been introduced³⁶. Food additives can be added to foods in reasonable contents and purposes to ensure quality traits, such as improving taste and appearance, protecting food from contamination by microbes or enzymes, preventing oxidation of oil containing unsaturated fatty acids³⁷. However, overdose or off-label use of illegal food additives and adulterants can be considered intended food contaminants. The potential of DART coupled to TOF-MS without pretreatment was verified by rapid analysis of various additives, including antimicrobial preservatives (benzoate, sorbic acid), artificial sweeteners (aspartame, acesulfame K), acidifiers (citric acid) and non-artificial compositions, for example, saccharides (hexose, disaccharide) and vitamins (ascorbic acid)³⁸.

Accidental contaminants: by-products of food processing:

In food processing, by-products can be generated due to improper practices and induce some undesirable consequences for our health. 3-chloropropane-1,2-diol (3-MCPD) and some other chloropropanols represent an important group of food processing by-products found in certain foods, such as edible oils, soy sauces, meats and dairy products³⁹.

C. Storage and transport:

Contaminants induced by microorganisms: mycotoxins:

Due to the lack of sterilization and disinfection, live bacteria and fungi will remain in the processed foods, leading to the generation of toxins or other metabolites during the storage and transport processes. In other cases, some metabolites are so stable that they cannot be easily removed by conventional treatment strategies, so they will be stored and transported along with the FSC in the final processed foods⁴⁰. Mycotoxins represent a large group of naturally occurring chemical contaminants that originate from the secondary metabolism of pathogenic microscopic filamentous fungi that can infest various food crops, particularly cereals. Depending on their characteristics and concentration levels, mycotoxins can induce toxic effects in humans and/or farm animals⁴¹.

Contamination from materials in contact with food: migrating packaging and utensils:

In the storage and transportation process, food samples are prone to contamination due to the migration of food contact materials (FCMs) from food containers or utensils to food, which can lead to unacceptable changes in ingredients⁴². Components of food and even endanger human health. There are many migratory contaminations from various CAMs (e.g. plastic, aluminum foil and composite paper), containing multiple classes of additives such as plasticizers, photoinitiators, antioxidants, dyes, anti-grease, UV stabilizers, etc⁴³.

D. Dart against another source of environmental ions:

In the current decade, numerous new environmental ionization technologies have emerged as possible analytical tools, and some of them have been successfully applied in the food field⁴⁴. DART can be considered a member of the APCI-related ionization technique and is common to other techniques. In this group all use a heated gas stream derived from atmospheric components to generate analyte ions⁴⁵. The ionization process can be generated by electric discharge or ion evaporation, while desorption mechanisms mainly combine thermal desorption with pulse desorption⁴⁶. ESI related ionization techniques fall into another category where analyte molecules can be guided directly from gas samples to the ESI plume for ionization, or desorbed/sampled solid or liquid samples before being transported to the gas spectrometer.

E. Forensic Applications of DART-MS:

Analysis of seized drugs:

The analysis and detection of drugs of abuse is one of the most sought after applications of DART-MS. First demonstrated in the landmark article, research involving this class of compounds has continued and grown steadily. Several new applications have been demonstrated in recent years such as species identification for psychoactive plants, the use of TD-DART-MS to allegedly identify drug test content, classification of cathinones by neutral loss spectra, and quantification of a set of different compounds⁴⁷. 

This approach can be useful in identifying NPS that have never been seen before. Cathinone fragmentation pathways have also been studied in depth by Davidson et al. The identification of more traditional drug classes has also been explored in recent years. Chen et al. analyzed a number of drugs commonly added to beverages, including γ-hydroxybutyrate (GHB) and γ-butyrolactone (GBL). Recoveries of 40% to 90% were found for fortified drinks, compared to water, and differentiation between GHB and GBL in negative ionization mode was demonstrated⁴⁸.

Steroids and Supplements:

Steroids and supplement will feature another compost group of interest to the pharmaceutical community which is the DART-MS status demonstrated the detection of testosterone, analogue of testosterone and other steroids in tablets and oils, with verified by GCxGC-MS. Also the researchers completed a comprehensive analysis of another twenty steroids, concentrating its oil-based preparation, and showed both qualitative detection and quantification. I did not notice that the thermal decomposition of steroid esters is stable at the DART gas temperature above 400°C and did not highlight the importance of the distance parameter from the source to the MS, which appears to be neglected. This state is still discussing the use of CID for identification migration⁴⁹.

E-liquids:

An emerging area of research for drug testing over the past five years has emerged around the increase in the use and abuse of e-cigarettes (e-cigarettes). Liquids in electronic cigarettes (eliquids) are commonly made up of propylene glycol, glycerin, nicotine, and flavoring additives, but can easily be modified to contain other drugs of abuse. In 2016, Peace et al. highlighted the ability to directly analyze e-liquids using a combination of DART-MS and LC-MS. DART-MS successfully detected the main components (propylene glycol and glycerin), as well as nicotine and flavoring additives (eg, carvone, ethyl vanillin and methyl salicylate). Peace et al. also demonstrated the analysis of e-liquids containing marijuana, with detection of multiple cannabinoids and terpenes in addition to the aforementioned compounds⁵⁰.

Analysis of psychoactive plants:

The analysis of plants containing psychoactive compounds has also been an active research area in recent years. Researchers demonstrated the detection of cathinone and cathine in the stems and leaves of the Khat plant by direct sampling. Sciencetist developed a quantitative method for measuring mitragynine in kratom plants. Using deuterated mitragynine as an internal standard, the samples (consisting of fresh plant material, dry plant material and powder) were soaked overnight in methanol, prepared and analyzed. Concentrations of mitragynine ranging from 2 mg/g to 20 mg/g have been found, but have not been independently verified. Although the detection of drugs and other psychoactive substances inside and outside plants has been shown, several studies have investigated the ability to use mass spectra for species identification^47,48.

Combination of DART-MS with other analytical techniques:

Several studies have shown that merging DART-MS data with data from other techniques can provide greater confidence in identification. More recent work has expanded to use nitrogen as an ionization gas, demonstrating changes in the distributions of dominant ions and adducts. Numerous studies have demonstrated the robust capabilities of DART-MS to directly interrogate surfaces of interest for pre- and post-explosion debris. These studies demonstrated the detection of surfaces including various metals, wood, glass, foam, asphalt, tape, Nomex, polytetrafluoroethylene (PTFE), polymer/metal cables, cell phone components and batteries. Thermal properties also played a role. For example, thermally conductive substrates heat up faster and over a larger area than insulators, effectively increasing the queried desorption area.

Inks and documents, and paint:

Inks and varnishes analysis has been active research areas for DART-MS for many years and focuses on similar types of compounds for detection. In both questions, the objective of the exam is usually guided by the need to compare a questioned with a known one, in cases of hit and run (paintings) or falsification of documents (inks). DART-MS was exploited for these samples for its ability to detect not only organic pigments but also other organic compounds within these matrices. Two studies, completed by researchers, and they investigated the use of DART-MS to classify and differentiate different types of printer ink samples. Both studies used the same set of swatches covering the different types of printer inks (inkjet, toner, offset and intaglio)⁴⁹.

Lubricants:

A unique area where DART-MS is increasingly being used is in the analysis of sexual lubricants. The analysis of these lubricants can be crucial in cases of sexual assault where there is no DNA evidence, providing a potential mechanism for correlating known and interrogated samples. Although the first case of DART-MS analysis of lubricants was reported in 2012, several recent studies have been conducted, mainly focusing on the classification and correlation of different classes of lubricants⁵⁰.

F. Other applications:

In addition to these frequently proven forensic analyzes, DART-MS has been applied to the identification and classification of regulated species (e.g., wood and rhino horn), entomology, polymers, adulterant beverages, and a number of other applications. The ability to directly and rapidly analyze single samples without extensive sample preparation provides interesting capabilities for the selection of regulated wood species. Traditionally, the anatomy of wood is used to identify endangered or prohibited species, regulated by the CITES treaty - Convention for the International Trade in Endangered Flora and Fauna, however many species often have indistinguishable characteristics. Evans et al. and Espinoza et al. used DART-MS in the direct analysis of wood chips in positive MS mode. In combination with supervised statistics (e.g. kernel discriminant analysis (KDA) on selected diagnostic ions) and unsupervised statistics (e.g. HCA), Dalbergia and Araucaria species were successfully classified and differentiated from similar species^51,52.

CONCLUSION:

DART-MS is the rapid, and extraordinary technique which is used for the identifications of many compounds. The basic concept of DART-MS include the primary ionization source which an entrance of gases. Also, we can classify the techniques which their mechanism of working. There are some natural plants which are discovered by direct real time mass spectroscopy technique like plant tissue, seed, extract, insect cuticle, hemolymph, microbe colony, and supernatant etc. Applications of DART-MS in food safety analysis were studied in which the production of food, detection of residue from drugs, analysis of raw material etc. Also, the forensic applications of direct real time analysis in the analysis of seized drugs, steroids, and supplements preparation, electronic liquid preparation, analysis of psychoactive plants etc. The printer inks were prepared by using this technique for sample determination in inks. So, we concluded that this technique were very helpful with wide range of applications, and in this study we justify the right use of DART-MS technique, or the basic concept of direct real time analysis.

ACKNOWLEDGEMENT:

The author wishes to acknowledge Laureate Institute of Pharmacy, Jawalamukhi, Himachal Pradesh (176031) for providing their support, and other required facilities in the preparation of this review article.

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Received on 26.03.2021       Modified on 17.04.2021

Accepted on 01.05.2021      ©Asian Pharma Press All Right Reserved

Asian J. Pharm. Ana. 2021; 11(3):243-251.

DOI: 10.52711/2231-5675.2021.00042