Time-of-flight Mass Spectrometry Research Articles

Chemical constituents from Mytilaria laosensis Lec. leaves and branches

Phytochemical investigations on the leaves and branches of Mytilaria laosensis Lec. led to the isolation of eight compounds, including four ecdysteroids (1-4), three flavonoids (5–7), and one phenylpropanoid (8). The identification of isolated compounds was achieved on the basis of NMR data, mass spectral data, and comparison with previous literature data. These eight compounds were isolated from M. laosensis for the first time. In addition, compounds 1–4 and 8 were found for the first time in the Hamamelidaceae family. Furthermore, the metabolite profiling of ethyl acetate and n-butanol fractions of M. laosensis were also measured by using liquid chromatography coupled with ion trap and time of flight mass spectrometry (LCMS-IT-TOF). The results of LCMS-IT-TOF analysis showed that this plant has other ecdysteroids and glycosides besides the eight isolated constituents. The chemotaxonomic significance of these compounds was discussed.

Chemical elucidation of recycled plastic pyrolysis oils by means of GC×GC-PI-TOF-MS and GC-VUV

Detailed chemical characterization of the composition of pyrolysis oils produced from plastics is a mandatory step in understanding the recycling process. Even though the chemical composition of pyrolysis plastic waste oils shows similarities with fossil-based oils, e.g. PIONA related compounds, the relative proportions of the chemical classes are significantly different, resulting in important changes in the global properties of these fluids. In this context, an analytical method based on comprehensive two-dimensional gas chromatography (GC×GC), coupled with photoionization (PI) – time-of-flight mass spectrometry (TOF MS) was developed to obtain a detailed chemical characterization of plastic pyrolysis-oil. A group-type analysis was achieved thanks to the detection of molecular ions by soft ionization PI-TOF MS. Moreover, olefins were successfully distinguished from naphthenes by in-depth consideration of MS spectra, even though such compounds elute very close in the 2D chromatographic separation space. A part of the olefins identified by PI was further confirmed by GC coupled to vacuum ultraviolet detection (VUV) since olefins VUV spectra differ from other compounds. The overall combination of the entire set of data of this multi-modal approach was valuable in studying the pyrolyzed plastic oil composition. It was furthermore applied to monitor the efficiency of upgrading processes that were applied to the oils to remove specific contaminants such as the diolefins. This approach has the potential to support the production of plastic pyrolysis oils that could efficiently be reintroduced in the market to sustain economic circularity needs.

Development and Validation of LC-MS/MS Method for Determination of Cytisine in Human Serum and Saliva.

Cytisine (CYT) is a quinolizidine alkaloid used for nicotine addiction treatment. Recent clinical trial data regarding cytisine confirm its high effectiveness and safety as a smoking cessation treatment. CYT's popularity is growing due to its increased availability and licensing in more countries worldwide. This increased use by smokers has also resulted in an urgent need for continued drug research, including developing appropriate analytical methods for analyzing the drug in biological samples. In this study, a simple, fast, and reliable method combining hydrophilic interaction liquid chromatography and electrospray ionization quadrupole time of flight mass spectrometry (HILIC/ESI-QTOF-MS) for the determination of CYT in human serum and saliva was developed and validated. This was undertaken after the previous pre-treatment of the sample using solid-phase extraction (SPE). A hydrophilic interaction liquid chromatography (HILIC) column with a silica stationary phase was used for chromatographic analysis. In a linear gradient, the mobile phase consisted of acetonitrile (ACN) and formate buffer at pH 4.0. The proposed method was fully validated and demonstrated its sensitivity, selectivity, precision, and accuracy. The method was successfully applied to determine CYT in serum and, for the first time, in saliva. The findings indicate that saliva could be a promising non-invasive alternative to measure the free concentration of CYT.

Influence of environmental settings in geographically distinct ports on the protein profiles of cultivable bacteria using MALDI–TOF mass spectrometry

AbstractThe protein profiles of bacteria are useful markers in their identification. In this study, we examined the influence of environmental settings on the protein profiles of culturable bacteria using matrix‐assisted laser desorption ionization‐time of flight mass spectrometry (MALDI–TOF MS). We compared the protein profiles of bacteria collected from geographically distinct port environments (Kolkata, a freshwater port, and Kandla, a marine port) from India. The results indicated that bacterial species were distinctly different between the two ports, except for a few bacteria, that were common, such as Bacillus cereus, Enterobacter cloacae, Micrococcus luteus, Pseudomonas aeruginosa, P. putida, P. stutzeri, P. mosselii and Vibrio parahaemolyticus. Mass spectra of these common bacterial species, a few pathogenic among them, differed in their protein profiles and relative intensity of peaks. These variations point out that environmental settings/factors have a significant role in the protein expression and can result in differentiated virulence of pathogens. Identifying these risk factors is crucial in developing appropriate environmental port management practices.

Boiling point modeling for petroleum speciation data

An empirical model is presented for generating the boiling curve of a petroleum sample based on parameters that are experimentally available using typical speciation techniques. The approach estimates the boiling point distribution of the detected components and allows a comparison with the simulated distillation profile of the sample. The model is shown to predict the boiling behavior of the speciation-derived average components in crude oil distillation fractions, which match the measured average distillation temperature of the fractions. The model is then applied to generate boiling distributions, based on mass spectrometric and gas chromatographic speciation data, which match the measured simulated-distillation curves with less than 20 °C difference. The model is also applied to the isolated fraction of saturated compounds, where the modeled boiling profile matches well with the measured distillation profile of the entire sample. This confirms that the model, although built using Fourier transform ion cyclotron resonance mass spectrometry data of aromatic compounds, extends to data obtained using comprehensive 2-dimensional gas chromatography, and also describes the boiling behavior of saturated compounds speciated by field desorption time of flight mass spectrometry. Consequently, the modeled boiling distribution enables an assessment of how well a speciation measurement describes the sample, and provides an estimation of lower and higher-boiling portions that have been omitted in the data set.

Escherichia coli Isolation, Prevalence, and Multi Drug Resistance from a Poultry Farm in Sendafa Town, Central Ethiopia

Background: Escherichia coli is bacteria that exist as commensal in the intestine of animals and humans, but pathogenic strains cause disease in chickens. The growth of antimicrobial resistance in E. coli is one of major concern worldwide. Objective: This study aimed to assess the prevalence, and Multi drug resistance profile and determine the potential risk factor of E. coli isolates from chickens and chicken’s environment in Sendafa town, central Ethiopia. Methods: A cross-sectional study was carried out from January to August 2023 in Sendafa town. Purposive sampling techniques were used based on the presence of clinical symptoms suggestive of E. coli in chicken farms. Different types of samples were collected including 207 cloacae swabs, 8 feed, and 8 water from different farms. E. coli isolation and identification were done using bacterial culture, and biochemical, and confirmed using the Matrix Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI TOF MS). Antimicrobial susceptibility testing (AST) was done using the Kirby Bauer disc diffusion method. Data were entered in Microsoft Excel and analyzed with descriptive statistics using SPSS version 20. Result: Out of a total of 223 samples of cloacae swab, feed, and water 71 (31.83 %) were found to be E. coli suspected by biochemical and finally confirmed with Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI TOF MS). All confirmed isolates were subjected to 12 antimicrobial agents to check their susceptibility. From 71 tested Escherichia coli isolates we found resistant patterns of E. coli to 62(87.3%) Amoxicillin, 44(62%) Tetracycline, and 39(54.9%) Streptomycin respectively. Multi-drug resistance was observed in this study for two or more than resistant detected. Some isolate was sensitive to 60(84.5%) Trimethoprim Sulphamethoxazole, 57(80.3%) Norfloxacin, 56(78.9 %) Ceftriaxone, and 53(74.6%) Meropenem respectively. Intermediate antibiotics were observed on 32(45.1 %) Sulfonamides, and 23(32.4%) Gentamicin for Escherichia coli isolate. Risk factors were analyzed with descriptive statistics. In the study, the difference in E. coli prevalence by age and among sample types was not statistically significant (P>0.05). Between kebele and farm, there was a statistically significant difference in E. coli prevalence (P <0.05). Conclusion: In this study, a high incidence of E. coli and antibiotic resistance to commonly used antibiotics including Amoxicillin, Tetracycline, and Streptomycin in poultry were found. This implies that there is the existence of practices that accelerate antimicrobial resistance in the sampled chickens therefore, appropriate use of antimicrobial agents, good biosecurity measures, and hygiene practices in chicken farms are important.

Closing the Gap in Proteomic Identification of Histoplasma capsulatum: A Case Report and Review of Literature.

Histoplasmosis is a globally distributed systemic infection caused by the dimorphic fungus Histoplasma capsulatum (H. capsulatum). This fungus can cause a wide spectrum of clinical manifestations, and the diagnosis of progressive disseminated histoplasmosis is often a challenge for clinicians. Although microscopy and culture remain the gold standard diagnostic tests for Histoplasma identification, matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) has emerged as a method of microbial identification suitable for the confirmation of dimorphic fungi. However, to our knowledge, there are no entries for H. capsulatum spectra in most commercial databases. In this review, we describe the case of disseminated histoplasmosis in a patient living with HIV admitted to our university hospital that we failed to identify by the MALDI-TOF method due to the limited reference spectrum of the instrument database. Furthermore, we highlight the utility of molecular approaches, such as conventional polymerase chain reaction (PCR) and DNA sequencing, as alternative confirmatory tests to MALDI-TOF technology for identifying H. capsulatum from positive cultures. An overview of current evidence and limitations of MALDI-TOF-based characterization of H. capsulatum is also presented.

Al3+ selective ratiometric fluorescent and colorimetric chemoprobe and its practical applications in foods, test kits and Smartphone

We herein developed an effective colorimetric and ratiometric fluorescent chemoprobe MPIM and successfully revealed its efficiency for naked eye recognition of Al3+ in MeOH/HEPES (6/4, v/v, pH = 7.4). Upon exposure of MPIM to diverse amounts of Al3+, the detection limit values for Al3+ were found as 12.6 µM and 1.82 μM, respectively. The MPIM was practically efficient and excellently selective for Al3+ in the existence of potentially competitive ions. The MPIM could be regenerated from MPIM–Al3+ complex with an appropriate agent of F–. The binding phenomenon of MPIM–Al3+ (2:1) was authenticated using Job's plot, FT–IR, 1H NMR titration and MALDI TOF–MS, and it was supported by DFT. Furthermore, the practical utilities of our prototype chemoprobe were clarified for Al3+ in diverse products, Smartphone and test kits applications without the aid of any sophisticated tool.

Condensed tannins from the leave of Dimocarpus longan Lour. exhibit anti-tyrosinase, anti-melanogenesis, anti-browning, anti-α-glucosidase, and anti-glycation activities

Dimocarpus longan Lour. is a valuable industrial crop for its broad applications in food, traditional Chinese medicine, and other fields. In this paper, condensed tannins were isolated from the leave of D. longan Lour., and their structure, anti-tyrosinase, anti-melanogenesis, anti-browning, anti-α-glucosidase, and anti-glycation properties were methodically clarified. The joint application of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), electrospray ionization time-of-flight mass spectrometer (ESI+ TOF MS), and high-performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS) confirmed that the longan leave condensed tannins (LLCTs) were polymers of procyanidins (majority) and prodelphinidins. The polymers powerfully inhibit tyrosinase (TY) with a competitive mechanism. These compounds altered the microenvironment of the binding site through hydrophobic interaction and hydrogen bond, and caused conformational modification of the enzyme by changing the polypeptide framework and secondary structure, leading to a decrease in TY activity. Cell assays further suggested that LLCTs exhibited a strong inhibition against intracellular TY activity and melanin production, and caused apoptosis in B16F10 cells. Anti-browning studies demonstrated that LLCTs suppress the browning of fresh-cut apples. Furthermore, the LLCTs exhibited an impressive inhibition on both α-glucosidase and nonenzymatic glycation. Therefore, this study confirms the potential of LLCTs as new inhibitors of tyrosinase, melanogenesis, browning, α-glucosidase, and nonenzymatic glycation, which provided a theoretical basis for the potential utilization of these polymers in the cosmetics, pharmaceutical, and food industries.

Influence of genetic variants and sialylation of purified κ-casein on peptide release during in vitro digestion

In the present study, digestion pattern of purified bovine κ-casein (κ-CN) variants A, B, E as well as desialylated variant B, using INFOGEST 2.0 in vitro gastrointestinal digestion were investigated using peptidomics. Peptide profiles of the digests were identified and quantified using ion abundancies by liquid chromatography electrospray quadropole time of flight mass spectrometry (LC-ESI/Q-TOF MS/MS). Results showed that the κ-CN variants A and E had comparable digestion patterns at most digestion time points. In the in vitro gastric and in the initial intestinal phases fewer peptides and with lower total abundances were identified for variant B compared to variants A and E, indicating a slower digestion rate for κ-CN B. By desialylation, the digestion rate of desialylated variant B in both gastric and initial intestinal phases increased compared to the natural sialylated counterpart. Bioinformatics search revealed nine potential bioactive peptides released from all three variants A, B and E by the in vitro intestinal digestion, with four additional potential bioactive peptides being released after desialylation of κ-CN B.

Molecular epidemiology and antibiotic resistance of Pseudomonas aeruginosa isolated from blood in a hospital in Shandong Province from 2014 to 2021

Objective: To identify the antibiotic resistance, virulence genes, and sequence types of Pseudomonas aeruginosa (P. aeruginosa) strains isolated from blood. Methods: From November 2014 to December 2021, a total of 94 nonrepetitive P. aeruginosa isolates were obtained from blood samples of patients at the First Affiliated Hospital of Shandong First Medical University in Shandong Province, China. The bacteria were identified using matrix-assisted laser desorption ionization time of flight mass spectrometry. Antibiotic resistance of the P. aeruginosa isolates was detected using Vitek 2 Compact system. Polymerase chain reaction (PCR) was conducted for the 18 virulence genes, and multi locus sequence typing (MLST) was performed to identify the sequence types of the P. aeruginosa strains. The resistance rates and distributions of virulence genes between carbapenem resistant pseudomonas aeruginosa (CRPA) and carbapenem susceptible pseudomonas aeruginosa (CSPA) isolates were compared using the Chi-square test. Results: Among 94 P. aeruginosa isolates, 19 (20.2%) isolates were found to be multidrug resistant (MDR) bacteria, of which 17 were CRPA isolates and 2 were CSPA isolates. All strains contained more than 10 virulence genes. Except for exoU gene, the detection rate of other genes was above 83%. MLST analysis revealed a total of 66 different STs, including 59 existing STs and 7 novel STs. Among them, ST244 (n=11, 11.7%) and ST270 (n=7, 7.4%) were the dominant STs. Although these two types of isolates harbored the same virulence genes, the resistance rates to carbapenem were different. 54.5% (6/11) ST244 isolates were CRPA but all 7 ST270 isolates were CSPA. Conclusion: Although the resistance rates of P. aeruginosa strains isolated from blood were at a low level, some MDR and CRPA isolates were detected. As the high virulence gene detection rates and genetic diversity were found for P. aeruginosa strains isolated from blood, close attention should be paid to avoid transmission and outbreaks.

Marine antifouling properties of enzyme modified polyaniline coated stainless steel surface

On solid surfaces immersed in a liquid medium, a biofilm layer which is called biofouling formed over time by organic molecules and microorganisms. It is important to produce new eco-friendly ideas can prevent this undesired phenome. In this study, we focused on the antifouling performance of polyaniline (PANI), whose anticorrosive properties have been already known. The main purpose of this study was to immobilize hydrolytic enzymes that could break down biomolecules and microorganisms and how this would contribute to the antifouling performance of the PANI coating. When α-amylase, DNAse, glucose oxidase, α-chymotrypsin, lipase and pectinase enzymes immobilized into PANI that was synthesized in ammonium oxalate (PANIAO) and sodium salicylate (PANISS) electrolytes, α-amylase containing film (PANISS-A) showed the highest performance (76.5% antifouling activity). The surface properties after keeping in the Mediterranean Sea for 12 days were compared by digital photography, Scanning Electron microscope (SEM) and fluorescence microscope images, also with Energy Dispersive X-Ray (EDX) analysis and crystal violet staining. Carbohydrate and protein amounts and CFU (Colony Forming Units) values of biofilms formed on the surface for bare, PANISS and PANISS-A coupons after keeping 12 days in the Mediterranean Sea were determined. Vibrio species (V.harveyi, V.alginolyticus, V.parahaemolyticus) were detected in the biofilms by Matrix- Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS) analysis.

Contaminated fungi in dried salted fishes: Isolation, identification, and their inhibition by chitooligosaccharide-gallic acid conjugate.

Contaminated fungi on dried salted fish of three species including Talang queenfish (TQF, Scomberroides commersonianus), Hamilton's thryssa fish (HTF, Thryssa hamiltonii), and Cobia fish (CF, Rachycentron canadum) were isolated and identified. One hundred and sixty-nine isolates were obtained from TQF and HTF, respectively, while no fungi were detected in CF. The dominant genera were Aspergillus spp. (n =79), Penicillium spp. (n =60), and non-sporulating fungi (n =30). The representative groups of Aspergillus spp. (n =6) and Penicillium spp. (n =3) based on different morphological characteristics were selected for species identification by molecular methods involving ITS1-5.8s-ITS2 region and Matrix-Assisted Laser Desorption/Ionization Time-of Flight Mass Spectrometer (MALDI-TOF MS)analysis. The nine isolates were identified to be Aspergillus versicolor (n =2), Aspergillus montevidensis (n =3), Penicillium citrinum (n =3), and Aspergillus sp. (n =1). The antifungal activity of chitooligosaccharide-gallic acid (COS-GAL) conjugate against A. versicolor F1/10M9, A. montevidensis F1/30M20, and P. citrinum F1/23M14 was examined. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) values were in the range of 0.625-2.5mg/mL and 1.25-10mg/mL, respectively. COS-GAL conjugate at the concentration of 5mg/mL completely inhibited the spore germination of A. versicolor F1/10M9 and P. citrinum F1/23M14 after 72h of treatment. COS-GAL conjugate at 4×MIC mainly affected the mycelium of A. versicolor F1/10M9 and P. citrinum F1/23M14 after treatment with COS-GAL conjugate for 3 days by coating mycelium surface and reducing the size of mycelium. Therefore, COS-GAL conjugate could be used as a food additive to inhibit or prevent the growth of fungi contaminated in dried salted fish or other relevant products. PRACTICAL APPLICATION: During processing, dried salted fish can be contaminated with fungi, which may cause food poisoning and food spoilage. The contaminated fungi are capable of producing mycotoxin that is harmful to consumers. Synthetic food preservatives have long been used to inhibit fungal growth, but the side effects to consumers are of concern. Chitooligosaccharide is a nontoxic chitosan derivative produced from shrimp shell and its conjugate namely chitooligosaccharide-gallic acid conjugate showed high efficacy in inhibiting the growth of fungi including Aspergillus spp. and Penicillium spp. Therefore, it can serve as a natural alternative preservative for the prevention of fungal growth in dried salted fish.

Surface-Assisted Laser Desorption/Ionization Mass Spectrometry Analysis of Latent Fingermarks Using Greenly Synthesized Silver Nanoparticles

Advances in nanotechnology have contributed to many innovative approaches in the forensic sciences, including the development of new techniques and protocols for latent fingermark detection. Among other nanomaterials, metal-based nanoparticles have been explored as suitable developers for fingermarks present on surfaces that challenge traditionally established methods. The present study explored, for the first time in the forensic science literature, the application of greenly synthesized silver nanoparticles (AgNPs) for latent fingermark surface-assisted laser desorption/ionization mass spectrometry (SALDI MS) analysis. A leaf extract of a native plant from the Cerrado biome was used for green synthesis of the AgNPs, and their hydrodynamic diameter, polydispersity index (PdI), and Zeta potential values were evaluated. Latent fingermarks were produced by three distinct donors and treated with α-CHCA matrix or AgNP suspension and were further investigated using commercial matrix assisted laser desorption/ionization (MALDI)-TOF MS equipment in the m/z range of 100–1000. Characterization results of the AgNPs indicated an average hydrodynamic diameter of 25.94 ± 0.30 nm, a PdI of 0.659 ± 0.085, and a Zeta potential of −33.4 ± 2.6 mV. The silver ions detected showed a relative intensity at least 20× higher for greenly synthesized AgNPs than for AgNO3 suspension, which may be advantageous for the detection of molecular species, especially olefins, present in forensic traces. The AgNP-based SALDI MS approach for the analysis of latent fingermarks showed intense ions at m/z 106.9, 215.8, and 322.7, referring to silver cation species that have been reported as important internal calibrants. The detection of components from endogenous and exogenous sources in latent fingermarks was achieved using the present approach. Greenly synthesized AgNPs may offer a new cost-effective, eco-friendly, and easily scaled up method for application in the chemical analysis of fingermarks.

Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry as Internship Teaching Content in Laboratory Medicine.

Matrix-assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS) is one of the preferred detection techniques for identification of clinical microorganisms and it has the characteristics of rapid identification, simple operation, low cost, and updatable databases. For laboratory medicine undergraduates, clinical internship is an important stage for the connection of basic theoretical knowledge and clinical practice. Internship teaching choosing MALDI-TOF MS as the content will greatly increase the popularity and applicability of the new technology in the clinical microbiology laboratory. With the help of electronic databases on the network, we conducted a systematic review. According to the purpose of research, we singled out forty papers. Latest studies on history, basic principles, clinical features, and applications of MALDI-TOF MS and the internship teaching contents introducing new technologies are summarized and focused on. In internship teaching, firstly we explain the historical development, basic principle and widespread applications of MALDI-TOF MS in the identification of clinical pathogenic microorganisms and the detection of antibiotic resistance. Subsequently, we instruct the students to perform the experimental operations, analyze the common problems, and find solutions. Finally, we highlight quality control and laboratory biosafety. Most of the reviews published previously report the clinical features and applications of MALDI-TOF MS and the internship teaching contents choosing other new technologies. It is the first study selecting MALDI-TOF MS technology as an internship teaching content creatively. Primary outcome is that the students understand the theoretical knowledge in detail, master the operation skills of MALDI-TOF MS quickly, and obtain excellent internship performances in the clinical internship through the internship teaching. Secondary outcome is that it is a help to cultivate medical students' train of thought for scientific research and to understand the application of the new technology in clinical testing and scientific research. Laboratory medicine undergraduates should cherish the opportunity to learn the new technology during the internship period and should master basic principle and operation. As internship teachers, it is necessary to introduce the new technology to students during the internship and encourage undergraduates to cultivate creative and innovative thinking of scientific research.

A sensitive mass spectrometry-based method to identify common respiratory pathogens in children.

Public health threats posed by emerging respiratory infections are a significant concern, particularly in children and infants. Traditional culture-based detection methods are time-consuming and typically require 1-3 days. Herein, we developed and evaluated a 23-plex common respiratory pathogen mass spectrometry assay that enables the simultaneous detection of 18 common respiratory pathogens in children. This assay combines matrix-assisted laser desorption/ionization time of flight mass spectrometry with multiplex reverse transcription-PCR and targets 11 bacterial and 7 viral pathogens (including 10 subtypes), and two internal controls. The detection limit of the common respiratory pathogen mass spectrometry assay was as low as 1 copy/µL, with no cross-reactivity with other organisms. We assessed the clinical performance of the common respiratory pathogen mass spectrometry assay using respiratory samples from 450 children. The total 450 clinical specimens underwent analysis via matrix-assisted laser desorption/ionization time of flight mass spectrometry, and the outcomes were juxtaposed with those derived from real-time reverse-transcriptase PCR conducted concurrently. The concordance between these methods was 96.0%, and the multiple infection identification rate was 7.1%. This innovative approach enables the simultaneous analysis of numerous outcomes from a solitary examination across 192 specimens within a timeframe of approximately 7 hours, with a dramatically reduced sample use and cost. In summary, the common respiratory pathogen mass spectrometry assay is a sensitive, accurate, and cost-effective method for detecting common respiratory pathogens in children and has the potential to revolutionize the diagnosis of respiratory tract infections. IMPORTANCE This study aimed to present and evaluate a novel co-detection method that enables the simultaneous identification of 11 bacterial and 7 viral pathogens in about 7 hours using matrix-assisted laser desorption/ionization time of flight mass spectrometry. Our approach utilizes a combination of multiplex reverse transcription-PCR and matrix-assisted laser desorption/ionization time of flight mass spectrometry, which overcomes the limitations of conventional assays, which include a long assessment time, technical difficulty, and high costs. As a screening method for common respiratory pathogens in children, common respiratory pathogen mass spectrometry assay has the potential to revolutionize the diagnosis of respiratory tract infections by providing an accurate etiological diagnosis. The common respiratory pathogen mass spectrometry assay is expected to be a critical tool for the diagnosis of respiratory infections in children, offering a more efficient, cost-effective, and accurate approach for the detection of common respiratory pathogens.

B-311 Increasing Xylazine Findings in Clinical Samples

Abstract Background Xylazine is a veterinary tranquilizer first appearing in illicit fentanyl preparations in 2019. It is believed to extend a fentanyl high and is now more commonly used as its own drug of abuse. Clinically, xylazine is of concern as it does not respond to naloxone or other antidote during overdoses. There are many forensic findings of increasing xylazine use since its original appearance, but little in the literature concerning clinical xylazine findings, possibly because xylazine is rarely screened in routine drug screening. We sought to find clinical cases with positive xylazine results from 2019–2022. Determined data included demographics (where possible to discern), sex distribution, age ranges, and frequency. Methods We queried our laboratory information management system (LIMS) for reported xylazine findings under expanded clinical drug screen utilizing liquid chromatography time of flight mass spectrometry (LC-TOF) for screening and liquid chromatography tandem mass spectrometry (LC-MS/MS) for confirmation, and specific xylazine testing utilizing LC-MS/MS. Results In 1928 clinical cases reported between January 2019 and January 2023, the xylazine positivity rate increased from 1.28% (2021; n = 13 positive xylazine results) to 5.05% positivity (2022; n = 29 positive xylazine results) despite a significant decrease in panels and tests with xylazine ordered (n = 1008 in 2021, n = 574 in 2022). The ages of the patients ranged 0–57 years; eleven cases concerned pediatric patients. Of cases that indicated the sex of the patient, 69% were male (n = 29). These cases were found in ten different states (AZ, CT, DE, IN, MA, NJ, OH, PA, UT, VA), with 18 incidental findings. While other drugs were present in incidental finding cases, all cases with an incidental positive xylazine result were also positive for fentanyl and norfentanyl, and several cases were also positive for fentanyl analogues, most commonly 4-ANPP, which occurred in 50% of these cases. Conclusion Xylazine use continues to be on the rise and should be of concern for emergency medicine doctors, poison control centers, and clinical laboratories.

Rapid identification of Salmonella serovars Enteritidis and Typhimurium using whole cell matrix assisted laser desorption ionization – Time of flight mass spectrometry (MALDI-TOF MS) coupled with multivariate analysis and artificial intelligence

Salmonella is a common food-borne pathogen with Enteritidis and Typhimurium being among the most important serovars causing numerous outbreaks. A rapid method was investigated to identify these serovars using whole-cell MALDI-TOF MS coupled with multivariate analysis and artificial intelligence and 113 Salmonella strains, including 38 Enteritidis (SE), 38 Typhimurium (ST) and 37 strains from 32 other Salmonella serovars (SG). Datasets of ions (presence/absence) with high discriminative power were created using newly developed criteria and subject to multivariate analyses and eight artificial intelligence (AI) tools. Principal Component Analysis based on 55 or 88 selected ions separated SE, ST and SG without overlap on the first three principal components. Datasets were partitioned using five partitioning methods with 70% of samples for AI model training and 30% for validation. Of the eight AI models evaluated, high performance (HP) SVM and HP Neural were the top performers, identified three serovar groups 97% correctly on average (range 82%–100%) according to the validation results. Selection of serovar specific ions facilitated differentiation of serotypes using unsupervised model PCA and improved the accuracy of classification using AI significantly (p < 0.01). MALDI-TOF MS incorporated with advanced data processing and classification tools is a promising method to allow rapid identification of Salmonella serovars of concern in routine diagnostic laboratories.

Synthetic cannabinoids in hair-Prevalence of use in abstinence control programs for driver's license regranting in Germany.

Although the use, structural variety, and prevalence of synthetic cannabinoids (SCs) have steadily increased on the drug market, they are rarely analyzed in abstinence control programs for driver's license regranting. The aim of this study was to determine the SC prevalence in these programs by analyzing hair samples collected between March 2020 and March 2021 from various regions in Germany, mainly Bavaria (40%). Specimens were analyzed quantitatively for drugs of abuse and qualitatively for 107 SCs. Hair samples were screened by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and to search for unknown SC analogs, positive samples were additionally screened by liquid chromatography-high resolution time of flight mass spectrometry (LC-qTOF/MS). The analysis of 5097 hair samples resulted in 181 SC detections (3.6%), showing a wide range of 44 SCs, with up to 13 different compounds found in a single sample. The most prevalent compounds were 5F-MDMB-PICA and MDMB-4en-PINACA; furthermore, 10 new substances not initially covered by LC-MS/MS analysis were detected by LC-qTOF/MS. The SC positivity rate was comparable to cocaine (5.4%) and amphetamine (2.6%). Only in 35 cases (0.7%), SC analysis was requested by the clients, highlighting the insufficient coverage of SC consumption in the studied collective. In summary, hair sample analysis proved to be a valuable tool to monitor the use of SCs. In order to keep pace with newly emerging SC analogs, an up-to-date analytical method is essential. Prospectively, SCs should be more routinely screened in hair analysis for abstinence control to avoid cannabis substitution by SCs.

Comparative analysis of chemical components in fruits of Chebulae Fructus and its pulp based on chromatographic technology coupled with multivariate chemometric methods

Chebulae Fructus, was extensively used as a food supplement and medicinal herb, which contained two medicinal forms corresponding to the mature fruit of Chebulae Fructus (CF) and CF pulp. They were widely used in the Chinese clinical medicine and it played a significant role in the Mongolian and Tibetan medicine for the treatment of sore throat, asthma, diarrhea and other diseases. Both of them were recorded in the 2020 Edition (Volume I) of the Chinese Pharmacopoeia. However, the chemical components of CF and CF pulp have not been holistically explored, which seriously hindered its quality evaluation. This study investigated the overall chemical profile of the CF and CF pulp using ultra high-performance liquid chromatography coupled with quadrupole time of flight mass spectrometry (UHPLC-Q-TOF/MS) and ultra high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Sixty-four chemical components were tentatively identified, and 13 components were quantified in Chebulae Fructus. Furthermore, multivariate chemometric methods were applied to compare the differences among CF samples, and all samples were classified by orthogonal partial least squares-discriminant analysis (OPLS-DA) based on the 13 quantified compounds. The results showed that CF and CF pulp were clustered in two different areas. Ellagic acid, chebulagic acid, chebulinic acid, corilagin and pentagalloyl glucose were selected as the significant constituents to different of CF and CF pulp. LC-MS coupled with chemometrics strategy analysis could comprehensively evaluate the holistic quality of CF, which provided a necessary information for the rational development and utilization of CF and CF pulp resource.