Atmospheric Pressure Solids Analysis Probe Research Articles

Assessment of a Single Quadrupole Mass Spectrometer Combined with an Atmospheric Solids Analysis Probe for the On-Site Identification of Amnesty Bin Drugs.

The surging number of people who abuse drugs has a great impact on healthcare and law enforcement systems. Amnesty bin drug analysis helps monitor the "street drug market" and tailor the harm reduction advice. Therefore, rapid and accurate drug analysis methods are crucial for on-site work. An analytical method for the rapid identification of five commonly detected drugs ((3,4-methylenedioxymethamphetamine (MDMA), cocaine, ketamine, 4-bromo-2,5-dimethoxyphenethylamine, and chloromethcathinone)) at various summer festivals in the U.K. was developed and validated employing a single quadrupole mass spectrometer combined with an atmospheric pressure solids analysis probe (ASAP-MS). The results were confirmed on a benchtop gas chromatography-mass spectrometry instrument and included all samples that challenged the conventional spectroscopic techniques routinely employed on-site. Although the selectivity/specificity step of the validation assessment of the MS system proved a challenge, it still produced 93% (N = 279) and 92.5% (N = 87) correct results when tested on- and off-site, respectively. A few "partly correct" results showed some discrepancies between the results, with the MS-only unit missing some low intensity active ingredients (N-ethylpentylone, MDMA) and cutting agents (caffeine, paracetamol, and benzocaine) or detecting some when not present. The incorrect results were mainly based on library coverage. The study proved that the ASAP-MS instrument can successfully complement the spectroscopic techniques used for qualitative drug analysis on- and off-site. Although the validation testing highlighted some areas for improvement concerning selectivity/specificity for structurally similar compounds, this method has the potential to be used in trend monitoring and harm reduction.

ASAP-MS combined with mass spectrum similarity and binary code for rapid and intelligent authentication of 78 edible flowers

This is the first report to use Atmospheric Pressure Solids Analysis Probe (ASAP) for rapid and intelligent authentication of 78 edible flowers. Mass spectra of 451 batches were collected, with each run for 1–2 min. Experimental raw data was automatically extracted and aligned to create a MS database, based on which flowers were identified by MS similarity scores and rankings. To avoid background interference, top 25 ions of each flower were screened and gathered into an m/z pool containing 292 ions (+) and 399 ions (−). Binary sequence IDs were then generated by automatically assigning “1″ for presence and “0″ for absence, resulting in 78 binary codes. Binary code similarity with 78 IDs was used for authentication. Above two approaches were automatically performed by MATLAB, and compared to k-nearest neighbor model, and samples were all successfully identified (100 %). The proposed method provides a high-throughput authentication approach for large-scale food samples.

Versatile, Cheap, Readily Modifiable Sample Delivery Method for Analysis of Air-/Moisture-Sensitive Samples Using Atmospheric Pressure Solids Analysis Probe Mass Spectrometry.

A cheap, versatile, readily modified, and reusable glass probe system enabling delivery of solid air-/moisture-sensitive samples for mass spectrometric (MS) analysis using an Atmospheric pressure Solids Analysis Probe (ASAP) is described. The simplicity of the design allows quick and easy ASAP MS analyses of sensitive solid and liquid samples without the need for any modifications to commercially available vertically loaded ASAP mass spectrometers. A comparison of ASAP mass spectra obtained for metal complexes under air and an inert atmosphere is given.

Rapid screening of illegal additives in functional food using atmospheric pressure solids analysis probe coupled to a portable mass spectrometer

Pharmaceutical drugs like Sildenafil are illegally added to functional food such as nutritional supplements and herbal remedies to deliver drugs without a regular prescription to consumers. Rapid screening of illegal additives is desirable for the public security department. The seized samples are often large in number and unknown in composition; methods are needed for qualitative screening of unknown samples. Here, a new approach is presented based on atmospheric pressure solids analysis probe (ASAP) coupled with single-quadrupole mass spectrometer to rapidly screen 42 common illegal additives in six categories of functional food. The ASAP-MS method could be applied to solid or liquid sample analysis with a very simple pre-treatment and no LC chromatographic separation, using a home-built library; the identification of suspicious additives could be obtained rapidly. More importantly, the approach is sensitive enough for complex matrix samples like coffee samples. 21 batches of seized unknown samples were tested by the ASAP-MS, and the positive results were confirmed by LC-MS/MS(QQQ), indicating that the ASAP-MS method is effective and reliable. The ASAP-MS with home-built library is a promising method for rapid screening of illegal additives in functional food, which could be widely used in the grassroots police station that lack professional laboratory environment.

Fast and semiquantitative screening for sildenafil in herbal over-the-counter formulations with atmospheric pressure solid analysis probe (ASAP) to prevent medicinal adulteration

Herbal medicines are commonly used in many countries all around the world. In Western countries they are now gaining more and more popularity, whereas in countries like China and India they have been entrenched for millenniums. Some of these perceived herbal medicines claim to help when suffering from erectile dysfunction. Nevertheless, many of these products are adulterated with PDE5 inhibitors like sildenafil or α-blockers. Patients who suffer from high blood pressure sometimes resort to herbal products, as they are not allowed to take sildenafil because of negative drug-drug interactions with nitrates (often utilized as treatment for coronary diseases). Products which are then adulterated with PDE5 inhibitors, can seriously harm patients. Therefore, this study reports the instant screening of alleged herbal products by employing atmospheric pressure solids analysis probe and high-resolution mass spectrometry to determine adulterants. Three out of 12 investigated products contained sildenafil in ranges from 0.5% to 18%. Multivariate analysis of ambient mass spectrometry measurements revealed encouraging outcomes for distinguishing non-sildenafil and sildenafil adulterated samples. Atmospheric pressure solids analysis probe is therefore a promising method for the rapid determination of sildenafil in herbal products with possible downstream semiquantitative analysis.

Rapid Screening of Illegal Additives in Health Products Using Atmospheric Pressure Solids Analysis Probe Coupled to a Portable Mass Spectrometer

Rapid Screening of Illegal Additives in Health Products Using Atmospheric Pressure Solids Analysis Probe Coupled to a Portable Mass Spectrometer

Comparison of LC-ESI, DART, and ASAP for the analysis of oligomers migration from biopolymer food packaging materials in food (simulants)

Biopolymers based on polylactic acid (PLA) and starch have numerous advantages, such as coming from renewable sources or being compostable, though they can have deficiencies in mechanical properties, and for this reason, polyester resins are occasionally added to them in order to improve their properties. In this work, migration from a PLA sample and from another starch-based biopolymer to three different food simulants was studied. Attention was focused on the determination of oligomers. The analysis was first performed by ultraperformance liquid chromatography quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF–MS), which allowed the identification of the oligomers present in migration. Then, the samples were analyzed by two ambient desorption/ionization techniques directly coupled to mass spectrometry (ADI), direct analysis in real-time coupled to standardized voltage and pressure (DART-MS) and atmospheric pressure solids analysis probe (ASAP-MS). These methodologies were able to detect simultaneously the main oligomers migrants and their adducts in a very rapid and effective way. Nineteen different polyester oligomers, fourteen linear and five cyclic, composed of different combinations of adipic acid [AA], propylene glycol [PG], dipropylene glycol [DPG], 2,2-dibutyl-1,3-propanediol [DBPG], or isobutanol [i-BuOH] were detected in migration samples from PLA. In migration samples from starch-based biopolymer, fourteen oligomers from poly(butylene adipate co-terephthalate) polyester (PBAT) were identified, twelve cyclic and two linear. The results from ADI techniques showed that they are a very promising alternative tool to assess the safety and legal compliance of food packaging materials.Graphical abstract

First direct evidence of broomcorn millet (Panicum miliaceum) in Central Europe

Chemical analysis of archaeological objects is an important part of current investigations. In the presented study, a soil from an archaeological vessel from rescue excavation close to the village Držovice (Central Moravia Region, Czech Republic; findings dated to Eneolithic period) was analyzed using gas chromatography/mass spectrometry and firstly in archaeological science by atmospheric pressure solids analysis probe with atmospheric pressure chemical ionization mass spectrometry. Miliacin, a chemical marker of a broomcorn millet, was unambiguously confirmed by both techniques. The obtained results can help to understand the diet habits of Corded Ware population and connection between Central Europe and Asia, where broomcorn millet has been domesticated. The identification of miliacin as a “chemical imprint” of millet from the end of Eneolithic period of Moravia is therefore extraordinarily important.

Sampling and analyte enrichment strategies for ambient mass spectrometry.

Ambient mass spectrometry provides great convenience for fast screening, and has showed promising potential in analytical chemistry. However, its relatively low sensitivity seriously restricts its practical utility in trace compound analysis. In this review, we summarize the sampling and analyte enrichment strategies coupled with nine modes of representative ambient mass spectrometry (desorption electrospray ionization, paper vhspray ionization, wooden-tip spray ionization, probe electrospray ionization, coated blade spray ionization, direct analysis in real time, desorption corona beam ionization, dielectric barrier discharge ionization, and atmospheric-pressure solids analysis probe) that have dramatically increased the detection sensitivity. We believe that these advances will promote routine use of ambient mass spectrometry. Graphical abstract Scheme of sampling stretagies for ambient mass spectrometry.

Analysis of air-, moisture- and solvent-sensitive chemical compounds by mass spectrometry using an inert atmospheric pressure solids analysis probe.

A novel method has been developed that enables chemical compounds to be transferred from an inert atmosphere glove box and into the atmospheric pressure ion source of a mass spectrometer whilst retaining a controlled chemical environment. This innovative method is simple and cheap to implement on some commercially available mass spectrometers. We have termed this approach inert atmospheric pressure solids analysis probe ( iASAP) and demonstrate the benefit of this methodology for two air-/moisture-sensitive chemical compounds whose characterisation by mass spectrometry is now possible and easily achieved. The simplicity of the design means that moving between iASAP and standard ASAP is straightforward and quick, providing a highly flexible platform with rapid sample turnaround.

Mass spectrometric analysis of carisoprodol and meprobamate in rat brain microdialysates.

We report the evaluation of several mass spectrometry-based methods for the determination of carisoprodol and meprobamate in samples obtained from the rat brain by in vivo intracranial microdialyis. Among the techniques that aspire to perform analyses without chromatographic separation and thereby increase throughput, chip-based nanoelectrospray ionization and the use of an atmospheric pressure solids analysis probe fell short of requirements because of insufficient detection sensitivity and hard ionization, respectively. Although direct analysis in real time provided the required soft ionization, shortcomings of a tandem mass spectrometry-based assay also included inadequate detection sensitivity and, in addition, poor quantitative reproducibility. Therefore, liquid chromatography coupled with atmospheric pressure chemical ionization tandem mass spectrometry was developed to determine carisoprodol and meprobamate from artificial cerebrospinal fluid as the medium. No desalting and/or extraction of the samples was necessary. The assay, combined with in vivo sampling via intracranial microdialyis, afforded time-resolved concentration profiles for the drug and its major metabolite from the nucleus accumbens region of the brain in rats after systemic administration of carisoprodol. Copyright © 2016 John Wiley & Sons, Ltd.

Use of atmospheric pressure solids analysis probe time-of-flight mass spectrometry to screen for plasticisers in gaskets used in contact with foods.

Plasticisers are used in the PVC gaskets of metal closures on glass jars and bottles used for foods and beverages. They may migrate and so contaminate the packed foodstuff. The plasticisers are present in a high proportion and are often a complex mixture of substances leading to time-consuming analytical methodologies. This work describes a rapid screening method to identify the plasticisers used. Analysis was carried out by direct sampling of the gaskets using atmospheric pressure solids analysis probe (ASAP) with time-of-flight (TOF) mass spectrometry (MS) using a SYNAPT G2 HDMS system. The accurate mass information collected was then compared to a user-prepared database of plasticisers to aid identification. The rapid identification approach was shown to be successful for 24 gasket samples previously analysed by alternative more lengthy gas chromatographic (GC) methods. Quantification by dissolution followed by standard addition was also demonstrated to be reliable. The ASAP-TOFMS method is a useful technique for rapidly screening gaskets for the presence of plasticisers. It can be used to identify specific gaskets deserving of further quantitative analysis by chromatographic methods, saving time and money by avoiding unnecessary analyses. Copyright © 2015 John Wiley & Sons, Ltd.

Characterization of Extracts from Geting Bituminous Coal

Geting bituminous coal (GBC) was exhaustively extracted with isometric carbon disulfide/acetone at ambient temperature to provide twenty extracts and a residue. The extracts were characterized by gas chromatography/mass spectrometry (GC/MS), Fourier transform infrared spectroscopy, and atmospheric pressure solids analysis probe time-of-flight mass spectrometry. GBC and its residue were observed with a scanning electron microscope. The total extract yield is ca. 11.5%. The GC/MS-detectable compounds in extract 1 can be classified into alkanes, cyclanes, arenes, cyclenes, and heteroatomic compounds, among which arenes are predominant. The number of detected compounds decreases and they have higher molecular masses with increasing extraction times. The combination of multiple techniques facilitates understanding the molecular composition of the extractable species from coals.

Modification of a gas chromatography/atmospheric pressure chemical ionisation time-of-flight mass spectrometer as an alternative to automated atmospheric pressure solids analysis probe.

The atmospheric pressure solids analysis probe (ASAP) has been successfully introduced into laboratories as a routine analytical tool but the technique is labour-intensive and is not easily automated. This paper describes the modifications made to an existing atmospheric pressure gas chromatography (APGC) system to enable the automated analysis of samples that would have otherwise been analysed by ASAP. Liquid samples were injected into a 1 m piece of fused silica guard column using a standard split/splitless gas chromatography (GC) inlet, oven and autosampler. A novel timing delay circuit was developed and integrated into the system to control acquisition start times and a bespoke heating block/calibrant delivery system was used to transport either the calibration or reference compound into the ionisation source. The modified system has allowed the successful analysis of those samples requiring ASAP to be carried out in a fully automated manner using APGc. The analysis is rapid and can be carried out in less than 2 min. The results obtained are directly comparable with those obtained by ASAP. A typical mass accuracy of better than 5 mm/z units was achieved, allowing the molecules to be identified based on their elemental formulae. An existing APGC system has been successfully modified and is suitable for the automatic analysis of samples normally analysed by ASAP. The APGC instrument incorporates the use of a novel reference compound and delivery system which allows accurate mass measurements to be performed. This and the other modifications described have allowed the technique to be incorporated into an existing suite of mass spectrometry-based experiments for use in the characterisation of organic molecules.

Evaluation of atmospheric solids analysis probe mass spectrometry for the analysis of coal-related model compounds

An atmospheric pressure solids analysis probe (ASAP) was mounted on a commercial atmospheric pressure chemical ionization source with simple modifications. A series of coal-related model compounds (CRMCs) were analyzed using a time-of-flight mass spectrometry equipped with the ASAP ion source. The ionization mechanism and fragmentation pathways for CRMCs were investigated. The temperature of desolvation gas played a crucial role to the response signal, especially for the association behavior of CRMCs. With a fixed desolvation gas temperature, radical cation (M+) or protonated molecule ([M+H]+) was the predominant ion generated by corona discharge of ASAP depending on the temperature of drying gas. Fragment ions were produced from bridged bond breaking of the precursor ions, rearrangement reactions and loss of neutral fragments such as H2O, CH2O, CO, CH3OH and CO2. The fragmentation pathways can offer a better understanding of fundamental mechanism of chemical bond breaking for coal derivatives and further explore the application of coal directional conversion.

Characterization of Complex Polysorbate Formulations by Means of Shape-Selective Mass Spectrometry

Complex synthetic formulations based on polysorbates can be challenging to characterize. They may be composed of many similar products including those of the same molecular weight, which cannot be readily separated by separation science approaches. Carbon number variation and ethylene oxide distribution add to the complexity. The properties of these formulations will be dependent on the chemical structure and relative concentration of formulation components. Here we describe the use of two experimental approaches based on mass spectrometry to provide enhanced characterization of these formulations. The first utilizes an atmospheric pressure solids analysis probe to rapidly determine the percentage content of individual esters in a formulation. These are shown to be in good agreement with product specification sheets. In a second approach, mobility separation has been integrated into a MALDI-MS/MS experiment to categorize major, minor, and trace ingredients. Components of identical molecular mass in the polysorbate formulations have been separated by ion mobility and then fragmented for additional characterization. The rapidity and level of structural detail provided by these experiments offers a significant opportunity to develop practical screening methods for complex formulations.

ChemInform Abstract: Analytical Tools for the Analysis of Carotenoids in Diverse Materials

AbstractReview: 99 refs.

Evaluating Atmospheric pressure Solids Analysis Probe (ASAP) mass spectrometry for the analysis of low molecular weight synthetic polymers

Atmospheric pressure Solids Analysis Probe (ASAP) mass spectrometry has facilitated the ionisation of oligomers from low molecular weight synthetic polymers, poly(ethylene glycol) (PEG: M(n) = 1430) and poly(styrene) (PS: M(n) = 1770), directly from solids, providing a fast and efficient method of identification. Ion source conditions were evaluated and it was found that the key instrument parameter was the ion source desolvation temperature which, when set to 600 °C was sufficient to vapourise the heavier oligomers for ionisation. PS, a non-polar polymer that is very challenging to analyse by MALDI or ESI without the aid of metal salts to promote cationisation, was ionised promptly by ASAP resulting in the production of radical cations. A small degree of in-source dissociation could be eliminated by control of the instrument ion source voltages. The fragmentation observed through in-source dissociation could be duplicated in a controlled manner through Collision-Induced Dissociation (CID) of the radical cations. PEG, which preferentially ionises through adduction with alkali metal cations in MALDI and ESI, was observed as a protonated molecular ion by ASAP. In-source dissociation could not be eliminated entirely and the fragmentation observed resulted from cleavage of the C-C and C-O backbone bonds, as opposed to only C-O bond cleavage observed from tandem mass spectrometry.

Rapid Detection and Identification of Impurities in Ten 2-Naphthalenamines Using an Atmospheric Pressure Solids Analysis Probe in Conjunction with Ion Mobility Mass Spectrometry

The atmospheric pressure solids analysis probe (ASAP), in conjunction with ion mobility time-of-flight mass spectrometry (IM-ToF-MS), has been applied to the impurity profiling study of ten 2-naphthalenamines. The impurity profiles achieved by ASAP-IM-MS were compared with those obtained by liquid chromatography-electrospray ionisation-mass spectrometry (LC-ESI-MS). All the impurities at the level of 0.1 area % and above, except for one, detected by LC-ESI-MS, were also found by ASAP-IMS analyses. In addition, one non-polar compound was detected by ASAP-IM-MS alone. The IM-MS plot of ion drift time versus m/z values offered sufficient separation between the impurities with different m/z. Therefore, instead of LC as a separation tool, IM-MS is able to provide fingerprint profiling for the ten samples analysed. The time of each analysis has been reduced from 25 min by LC-MS to less than 3 min by ASAP-IM-MS. When collision energy was applied for the selected precursor ion in the transfer T-wave, a clean MS/MS spectrum was obtained for structural elucidation of unknown impurities. The hyphenation of ASAP and IM-MS techniques represents a highly efficient approach for rapid detection and identification of impurities generated in complex reactions involved in pharmaceutical development.

Analysis of nucleosides using the atmospheric-pressure solids analysis probe for ionization

Nucleosides are polar molecules and generally considered to be non-volatile. Therefore, electrospray ionization is the method of choice for analysis of these compounds by mass spectrometry. In this work, we demonstrate that the atmospheric-pressure solids analysis probe can be used to ionize modified and non-modified nucleosides. Analogously to atmospheric pressure chemical ionization, this ionization technique utilizes heat to vaporize the compounds and a corona discharge needle to ionize the vaporized analytes. The optimum source conditions were determined and the influence of temperature, the presence of cations and the nature of modification were investigated. It was found that nucleosides withstand the elevated temperature well and can be brought in the gas phase as neutral molecules. The generated fragmentations are comparable to those observed with electrospray ionization.