Search

Plastic sports-fields are commonly used in communities, schools and other public places nowadays, which can offer positive benefits to fitness and sports. Plastic sports-fields are usually made of petroleum-based materials. Under high-temperature weather, various potentially harmful volatile organic compounds (VOCs) can be released to the ambient air, which pose a potential health risk to people who are on the plastic sports-field or living near the plastic sports-field. In our previous work, an analytical tool for onsite investigation of air pollutants was developed by drone-based solid-phase microextraction (drone-SPME) coupled with portable gas chromatographymass spectrometry (PGC-MS). In this work, the drome-SPME-PGC-MS method was further used to analyze the air pollutants in the plastic sports-field. The volatile air pollutants such as benzothiazole and benzene were identified by NIST standard spectra and standard substances. The results showed that benzothiazole was released from the ground material of plastic sports-fields, while benzene was mainly released from the paint that was painted at the fence of plastic sports-fields. Analytical performances, such as sensitivity, reproducibility, and quantitation were investigated using drone-SPME-PGC-MS. The relative standard deviations (RSDs) of benzene (1.0 μg/L) and benzothiazole (1.0 μg/L) were 13.2% and 11.4% (n=6), respectively, indicating the high reliability of drone-SPME for air sampling. The limits of detection (LODs) of benzene and benzothiazole were 0.036 μg/L and 0.088 μg/L (S/N=3), respectively, showing good sensitivity for air analysis. The different concentrations of benzene and benzothiazole in a glass container were detected using this method, showing good linear responses (benzene: 0.044-2.20 μg/L, R2=0.992 9; benzothiazoles: 0.10-2.10 μg/L, R2=0.993 7). Moreover, benzene and benzothiazole in the air at different plastic sportsfields were quantitative detected by established drone-SPME-PGC-MS. Furthermore, the releases and distributions of benzothiazole and benzene at different temperatures (33, 12 ℃) and different heights (0.5-40 m) were investigated, showing that these air pollutants were mainly distributed at the ground layer (≤ 5 m) and were mainly released at high-temperature conditions (33 ℃). Overall, the drone-SPME-PGC-MS is a promising analytical method for the onsite investigation of air pollutants at the plastic sports-fields.

Copyright of Journal of Chinese Mass Spectrometry Society is the property of Journal of Chinese Mass Spectrometry Society and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Fumonisins are a group of mycotoxins that routinely contaminate maize. Their presence is monitored at multiple stages from harvest to final product. Immunoassays are routinely used to screen commodities in the field while laboratory-based methods, such as mass spectrometry (MS), are used for confirmation. The use of a portable mass spectrometer unlocks the potential to conduct confirmatory analyses outside of traditional laboratories. Herein, a portable mass spectrometer was used to measure fumonisins in maize. Samples were extracted with aqueous methanol, cleaned up on an immunoaffinity column, and tested with the portable MS. The limits of detection were 0.15, 0.19, and 0.28 mg/kg maize for fumonisins B1 (FB1), FB2/FB3, and total fumonisins, respectively. The corresponding limits of quantitation in maize were 0.33, 0.59, and 0.74 mg/kg. Recoveries ranged from 93.6% to 108.6%. However, RSDs ranged from 12.0 to 29.8%. The method was applied to the detection of fumonisins in 64 samples of maize collected as part of the Illinois Department of Agriculture's monitoring program. Good correlations were observed between the portable MS and a laboratory-based LC-MS method (r2 from 0.9132 to 0.9481). Results suggest the portable MS can be applied to the measurement of fumonisins in maize at levels relevant to international regulations. [ABSTRACT FROM AUTHOR]

Paper-capillary spray modified on the basis of paper spray ionization in order to facilitate the combination with portable mass spectrometry is an ambient ionization technique, which can be uesd to detect compounds rapidly without the restriction of location and environment. Paper-capillary spray and ambient ionization portable mass spectrometry in positive ion mode were used to collect mass spectrum information of 40 kinds of cathinones controlled in China. The ［M+H］+ peak of MS1, the characteristic fragment ions of MS2 and MS2_DDA mode and their relative abundance ratio were analyzed. The obtained mass spectrum information was used to establish a database for the rapid screening of 40 cathinones. It was found that C—N cleavage at the α site existed in all the cathinones through the study of their fragmentation characteristics. Whether the highest ion peak was ［M—H2O+H］+ fragment peak could infer the existence of secondary and tertiary amine structures. A series of characteristic peaks of m/z 98+CnH2n would exist when the N was substituted by pyrrolidinyl. The characteristic ion of ［M+H］+ lost 48 u or that of non ［M+H］+ lost 30 u would exist when the benzene ring was substituted by methylenedioxy. The fragmentation characteristics were studied to design and establish a complete analysis strategy for the unknown cathinones. The strategy could be applied in the following three aspects. 1) To judge whether they are cathinones; 2) To judge whether they are 40 kinds of cathinones in the database; 3) To infer the characteristic structure of cathinones outside the scope of the database. The strategy was successfully used for the structural identification of 10 analytes, which included the common categories of drugs controlled in China. No interference or misjudgment was found, and the database could be used normally. The structures inferred by the analysis strategy were consistent with the actual structure, and the isomers involved would also be distinguished because of their different fragment ions, indicating that this scheme was feasible. This method only needs simple sample loading operation and integrated small mass spectrometer, and is not limited by location and environment. In the investigation of such drug cases, this method can carry out rapid screening and timely feedback, which plays an important role in the rapid and accurate crackdown on the crime of cathinones and it is expected to be a new way to study and judge the crime of cathinones. [ABSTRACT FROM AUTHOR]

The Jatropha curcas plant (Jatropha) has been proposed as a source of biodiesel fuel, as it yields crude glycerol as an abundant by-product. Its by-products could serve as a starting material in making glycerol for FDA-regulated products. Jatropha is not regarded as a source of edible vegetable oil since it contains phorbol esters (PEs). PEs, even at very low exposure concentrations, demonstrate various toxicities in humans and animals, but may not be detected by routine impurity analyses. Here, we demonstrate the development of a rapid and simplified method for the detection and quantification of Jatropha-derived PE toxins using ambient ionization mass spectrometry. To do this, we successfully coupled a paper spray ambient ionization source with an ion trap portable mass spectrometer. The paper spray source was assembled using chromatography papers, and analyte ions were generated by applying a high voltage to a wetted paper triangle loaded with PE standards. For method development, we used commercially available PE standards on an ion trap portable mass spectrometer. Standard solutions were prepared using ethanol with PE concentrations ranging from 1.0 to 0.0001 mg mL−1. Spike and recovery experiments were performed using USP grade and commercially available glycerol. To discern chemical differences between samples, we applied multivariate data analysis. Based on the results obtained, paper spray coupled with a portable mass spectrometric method can be successfully adopted for the analysis of toxic contaminants present in glycerol-based consumer products with LOD and LOQ of 0.175 μg mL−1 and 0.3 μg mL−1 respectively. This direct, simple design, and low-cost sampling and ionization method enables fast screening with high sensitivity in non-laboratory settings. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A Hybrid Flowing Atmospheric PressureAfterglow(FAPA)-Differential Mobility Spectrometry (DMS) device is constructed. • Cobalt and nickel acetylacetonate complexes are deposited on mesh substrates for solid surface analysis by FAPA-DMS. • Rapid separation is achieved between complexes with different oxidation states. • FAPA-DMS permits speciation in a binary mixture of isobaric complexes of metal acetylacetonates. • FAPA-DMS demonstrates quantitative analysis of nickel acetylacetonate. Abstract Metal-ligand complexes are important analytical targets across environmental, industrial, security, and biological investigations. The various complex forms of these species calls for analytical techniques that can selectively detect them in their native (in-situ) environment. Fieldable screening technologies based on portable mass spectrometry (MS) require simplified sample-preparation and ionization methods. Therefore, various direct ambient desorption/ionization sampling methods, such as the flowing atmospheric-pressure afterglow (FAPA), are of high interest as portable tools and possess the capability to desorb/ionize complexed elemental species. With such sample introduction, matrix from ambient chemicals may interfere with the analyte of interest leading to false-positive detection. Differential mobility spectrometry (DMS) can provide additional post-ionization separation and reduction of interferences. Herein, we explore coupling a FAPA desorption/ionization source with DMS for the first time for metal-ion speciation. The FAPA-DMS hybrid was used for separation and detection of individual ionic species from cobalt and nickel complexes with acetylacetonate in standard mixtures. We observe a concentration dependence of the DMS separation in mixtures. Altered DMS dispersion behavior is attributed to high concentrations of desorbed neutral complexes acting as a gas-phase modifier. For the case of Ni(AcAc) 2 , solutions deposited from 100 to 1000 μg/mL exhibit good linearity when the DMS is employed. The results described herein suggest a method which may be used in in situ applications for inorganic complex analyses. [ABSTRACT FROM AUTHOR]

Rapid on-site screening of biogenic volatile emissions from leaves of living plants is demonstrated, using headspace solid-phase microextraction (HS-SPME) with a portable gas chromatograph (PGC), fitted with a low-thermal mass (LTM) column equipped with a miniature toroidal ion trap mass spectrometer (ITMS). For field sampling, the study was conducted at the Royal Botanical Garden, Cranbourne, Australia, with the sampling site located in the Peppermint Garden. Twelve designated plants in the families of Asteraceae, Lamiaceae, Myrtaceae, Pittosporaceae, and Rutaceae were chosen for this field study. A customised SPME syringe was used for headspace sampling and sample introduction; leaves were collected into vials, equilibrated, sampled onto a PDMS/DVB-coated fibre, then desorbed in the GC inlet in split mode. A resistively heated LTM, narrow bore (0.1 mm ID) non-polar capillary column heated at 2 °C s−1 to 270 °C, provided fast GC elution with total run time of 3 min. The miniaturised ITMS was operated over a mass range of 40-500 Da. This provided approximation of near-real-time measurement of leaf volatiles released from the plant. For a second study, PGC-ITMS is employed to profile essential oils from experimental hybrid and commercial Humulus lupulus L. (hop) plant extracts in the laboratory, and contrasted with bench-top data. Results were processed by chromatographic fingerprinting using retention times, and MS fragmentation pattern similarity criteria. Unsupervised multivariate analysis was performed to improve specificity for classification of different plant volatiles, yielding loading variables corresponding to chemical differences of the analysed plants. The combination of HS-SPME and portable GC-ITMS proved effective for rapid chemical expression of the plant volatile genotype in the field. [ABSTRACT FROM AUTHOR]

Active capillary dielectric barrier discharge ionization (DBDI) is emerging as a compact, low-cost, and robust method to form intact ions of small molecules for detection in near real time by portable mass spectrometers. Here, we demonstrate that by using a 10 kHz, ~2.5 kV high-voltage square-wave alternating current plasma, active capillary DBDI can consume less than 1 μW of power. In contrast, the power consumed using a sine and triangle alternating current waveform is more than two orders of magnitude higher than that for the square waveform to obtain a similar voltage for plasma generation. Moreover, the plasma obtained using a square waveform can be significantly more homogenous than that obtained using sine and triangle waveforms. Protonated dimethyl methylphosphonate (DMMP) and deprotonated perfluorooctanoic acid (PFOA) can be detected at about the same or higher abundances using square-wave DBDI mass spectrometry compared with the use of sine and triangle waveforms. By use of benzylammonium thermometer ions, the extent of internal energy deposition using square, sine, or triangle waveform excited plasmas are essentially the same at the optimum voltages for ion detection. Using an H-bridge circuit driving a transformer optimized to reduce losses, square-wave active capillary DBDI can be continuously powered for ~50 h by common 9 V-battery (PP3). [ABSTRACT FROM AUTHOR]

Portable mass spectrometers (MS) are becoming more prevalent due to improved instrumentation, commercialization, and the robustness of new ionization methodologies. To increase utility towards diverse field-based applications, there is an inherent need for rugged ionization source platforms that are simple, yet robust towards analytical scenarios that may arise. Ambient ionization methodologies have evolved to target specific real-world problems and fulfill requirements of the analysis at hand. Ambient ionization techniques continue to advance towards higher performance, with specific sources showing variable proficiency depending on application area. To realize the full potential and applicability of ambient ionization methods, a selection of sources may be more prudent, showing a need for a low-cost, flexible ionization source platform. This manuscript describes a centralized system that was developed for portable MS systems that incorporates modular, rapidly-interchangeable ionization sources comprised of low-cost, commercially-available parts. Herein, design considerations are reported for a suite of ambient ionization sources that can be crafted with minimal machining or customization. Representative spectral data is included to demonstrate applicability towards field processing of forensic evidence. While this platform is demonstrated on portable instrumentation, retrofitting to lab-scale MS systems is anticipated.

An expedited field analysis method was developed for the determination of polychlorinated biphenyls (PCBs) in soil matrices using a portable gas chromatography-mass spectrometry (GC-MS) instrument. Soil samples of approximately 0.5 g were measured with a portable scale and PCBs were extracted by headspace solid-phase microextraction (SPME) with a 100 µm polydimethylsiloxane (PDMS) fiber. Two milliliters of 0.2M potassium permanganate and 0.5 mL of 6M sulfuric acid solution were added to the soil matrices to facilitate the extraction of PCBs. The extraction was performed for 30 min at 100 °C in a portable heating block that was powered by a portable generator. The portable GC-MS instrument took less than 6 min per analysis and ran off an internal battery and helium cylinder. Six commercial PCB mixtures, Aroclor 1016, 1221, 1232, 1242, 1248, 1254, and 1260, could be classified based on the GC chromatograms and mass spectra. The detection limit of this method for Aroclor 1260 in soil matrices is approximately 10 ppm, which is sufficient for guiding remediation efforts in contaminated sites. This method was applicable to the on-site analysis of PCBs with a total analysis time of 37 min per sample. However, the total analysis time could be improved to less than 7 min per sample by conducting the rate-limiting extraction step for different samples in parallel. [ABSTRACT FROM AUTHOR]

Abstract: Development of miniaturized ion trap (IT) mass analyzers for portable mass spectrometry has taken advantage of the latest technology in conventional machining and microfabrication. Researchers are now turning to new materials, such as polymers and ceramics, as well as alternative electrode shapes and arrangements to create the precisely-shaped electric fields needed for good performance on small-scale devices. Polymer-based construction allows lightweight structures, complex shapes and inexpensive production of small ITs. Simplified electrode arrangements, such as ITs made from two patterned ceramic plates, allow precise electric fields and simplified electrode alignment. [Copyright &y& Elsevier]

Abstract: Membrane-introduction mass spectrometry (MIMS) for chemical analysis involves directly sampling analytes in gaseous, liquid and solid samples through a semi-permeable membrane coupled to a mass spectrometer, yielding selective and sensitive quantitation. Because MIMS is an on-line technique, in which samples can be continuously flowed over a membrane interface, it can yield analytical results in real time without the need for sample clean-up and chromatographic separation. This review highlights trends and developments in MIMS over the past decade and describes recent studies that pertain to its use for on-site, in-situ and in-vivo chemical analysis. We report on advancements in instrumentation, including membrane materials, interface configurations and ionization techniques that have extended the range of analytes amenable to MIMS. We summarize the progress made in the miniaturization of mass spectrometers that have resulted in field-portable systems and review recent applications of continuous mobile monitoring and on-site environmental monitoring to yield both temporally and spatially resolved quantitative and semi-quantitative data. Finally, we describe recent work involving the use of MIMS for in-vivo chemical analysis. [Copyright &y& Elsevier]

Abstract: Reduced power operation of a mass analyzer with minimum loss of spectral resolution and mass range is desirable in portable instruments. Miniaturizing quadrupole-based ion traps can be especially worthwhile since the RF amplitude necessary for mass analysis scales with the square of the analyzer dimensions. The performance of a miniature, stainless steel, rectilinear ion trap (RIT) with dimensions of 1.66mm×1.43mm (x 0 and y 0 respectively) is characterized by sampling externally generated ions and performing mass analysis without benefit of differential pumping to simulate conditions in a miniature system. This system is capable of detecting analyte ions of up to m/z 1250 at operating voltages of 610V0-p (drive frequency of 1.105MHz), and with spectral resolution on the order of 2Th (FWHM) across the entire mass range. The ability to acquire structural information through tandem MS is also demonstrated. [Copyright &y& Elsevier]

Five different classes of explosives were analysed by ambient ionisation mass spectrometry testing selectivity, sensitivity, and repeatability. We compare the effectiveness of two techniques (ASAP and SESI) for the trace detection of five explosives representative of the most common classes of high explosive: HMTD, RDX, PETN, Tetryl and TNT. Experiments also compared the effectiveness of sample loading via a glass fibre swab or glass rod. All analyses were carried out with a Waters Acquity QDa mass spectrometer, a small format mass spectrometer which can be operated in a transportable mode (using ambient air and a small diaphragm pump). Both ambient ionisation techniques, ASAP and SESI, successfully detected the five different explosives which could make them suitable for a screening method. By directly comparing a calibration range of 0.8–10 ng on both swabs and rods for each explosive, it appears that SESI produces less variability per repeat, particularly at the higher end of the range when compared to ASAP which typically has a lower limit of detection and better linearity. [Display omitted] • Portable mass spectrometer with ambient ionisation can detect a range of explosives. • Corona discharge and secondary electrospray provides limits of detection for aviation application. • Samples introduced using commercial fibre glass swabs and glass capillary rods. • Additional specificity from mass spectrometry can reduce false positive results. [ABSTRACT FROM AUTHOR]

• Small footprint LC-UV/MS system for pharmaceutical process monitoring. • In-fumehood reaction monitoring by LC-UV/MS. • Automated sample dilution, derivatisation, and delivery. • Multi-deep LED based absorbance detection with portable mass spectrometry. Liquid chromatography (LC) has broad applicability in the pharmaceutical industry, from the early stages of drug discovery to reaction monitoring and process control. However, small footprint, truly portable LC systems have not yet been demonstrated and fully evaluated practically for on-line, in-line or at-line pharmaceutical analysis. Herein, a portable, briefcase-sized capillary LC fitted with a miniature multi-deep UV-LED detector has been developed and interfaced with a portable mass spectrometer for on-site pharmaceutical analysis. With this configuration, the combined small footprint portable LC-UV/MS system was utilized for the determination of small molecule pharmaceuticals and reaction monitoring. The LC-UV/MS system was interfaced directly with a process sample cart and applied to automated pharmaceutical analysis, as well as also being benchmarked against a commercial process UPLC system (Waters PATROL system). The portable system gave low detection limits (∼3 ppb), a wide dynamic range (up to 200 ppm) and was used to confirm the identity of reaction impurities and for studying the kinetics of synthesis. The developed platform showed robust performance for automated process analysis, with less than 5.0% relative standard deviation (RSD) on sample-to-sample reproducibility, and less than 2% carryover between samples. The system has been shown to significantly increase throughput by providing near real-time analysis and to improve understanding of synthetic processes. [ABSTRACT FROM AUTHOR]

A fast non‐destructive approach based on the use of portable selected ion flow tube-mass spectrometry (SIFT-MS) was used for the first time to characterize organic materials in archaeological artifacts. The high sensitivity, specificity and selectivity SIFT soft chemical ionization mass spectrometry enabled us to investigate the composition of organic residues collected from ancient Egyptian findings in order to demonstrate the robustness of the techniques with different matrices. In addition, we tested SIFT-MS directly on an archaeological Egyptian amphora to prove its suitability as a completely non-invasive technique. Parallel investigations on all the samples were performed by GC/MS analysis to correlate and confirm the data obtained by SIFT-MS. The possibility of using a portable mass spectrometer on an excavation site or in a museum would be a significant step forward in the non-invasive analysis of organic archaeological materials, enabling archeologists and conservators to obtain real-time information on the molecular composition of organic residues. Image 1 • We used for the first time SIFT-MS for the analysis of archaeological samples. • We tested SIFT-MS directly on an Egyptian archaeological artifact (1990 - 1780 AC). • SIFT-MS allowed us to obtain results comparable with those obtained by GC/MS. [ABSTRACT FROM AUTHOR]