Treating hyperglycaemia in a patient with maternally inherited diabetes and deafness with an inhibitor of dipeptidyl peptidase-4: a case report and two-year follow-up.

Maternally inherited diabetes and deafness (MIDD) is a mitochondrial disorder with diverse characteristics, which make early diagnosis difficult. We report a case of 32-year-old woman with diabetes who was admitted due to weight loss and poor glycemic control. She had a history of gestational diabetes at age 26. Pancreatic function was evaluated by oral glucose tolerance. An ophthalmologic examination detected conjunctivitis and refractive errors and hearing tests were normal. The patient had a family of diabetes. Then we tested the patient and her first-degree relatives with a confirmed genetic mutation at position 3243 in the tRNA. After two years of treatment with linagliptin, both glycated hemoglobin and pancreatic function have shown improvement to some extent. Although MIDD is a rare form of diabetes, due to distinctive management and associated comorbidities it is important to diagnose.

Determination of multi-residue pesticides in dairy products using single-step emulsification/demulsification clean-up strategy combined with low-pressure gas chromatography-tandem mass spectrometry.

In this study, a simple, sensitive, and rapid method was developed for the simultaneous determination of 99 kinds of pesticides in fatty milk samples. This novel emulsification-demulsification clean-up approach, coupled with an automatic demulsification-dehydration cartridge, allowed rapid single-step clean-up operation and high throughput. It also achieved effective and selective removal of lipids. The analysis was performed using low-pressure gas chromatography-tandem mass spectrometry (LPGC-MS/MS). Based on the optimal conditions, the targeted pesticides showed good linearity in the range of 5-250 µg/kg, with recoveries of 70-120% at spiking levels of 5, 10, and 20 µg/kg in cow milk, goat milk, and almond milk, respectively. The limit of quantification for most pesticides was 5 µg/kg, and the RSDs were lower than 20%. Analysis of real dairy products obtained from local markets revealed a potential risk in plant-derived almond milk, but no significant risks were found for cow and goat milk.

Mass Spectrometry for Biomedical and Food Analysis.

Biomedical and food analysis has always been an important topic that closely relates to health [...].

Neonicotinoid insecticides in plant-derived Foodstuffs: A review of separation and determination methods based on liquid chromatography.

Neonicotinoids (NEOs) are the most widely used insecticides globally. They can contaminate or migrate into foodstuffs and exert severe neonic toxicity on humans. Therefore, lots of feasible analytical methods were developed to assure food safety. Nevertheless, there is a lack of evaluation that the impacts of food attributes on the accurate determination of NEOs. This review aims to provide a comprehensive overview of sample preparation methods regarding 6 categories of plant-derived foodstuffs. Currently, QuEChERS as the common strategy can effectively extract NEOs from plant-derived foodstuffs. Various enrichment technologies were developed for trace levels of NEOs in processed foodstuffs, and multifarious novel sorbents provided more possibility for removing complex matrices to lower matrix effects. Additionally, detection methods based on liquid chromatography were summarized and discussed in this review. Finally, some limitations were summarized and new directions were proposed for better advancement.

Purity Assessment of Dinotefuran Using Mass Balance and Quantitative Nuclear Magnetic Resonance.

Dinotefuran (DNT) belongs to the third-generation neonicotinoid pesticides, which are among the most common residuals in a variety of food commodities. To guarantee accurate quantification and traceability of results in food samples, certified reference materials (CRMs) are the indispensable benchmark. In this work, a DNT CRM was characterized and its purity was assessed by two independent methods, including mass balance (MB) and quantitative nuclear magnetic resonance spectroscopy (qNMR). The mass fraction of moisture was 0.33 mg/g, the inorganic impurity was 0.01 mg/g, and no detectable organic solvent was detected. Benzoic acid was chosen as the internal standard for qNMR. Its mass fraction was 997.9 mg/g and 992.9 mg/g by MB and qNMR, respectively. Eventually, the DNT CRM was assigned a mass fraction of 995 mg/g, with expanded uncertainty of 5 mg/g (k = 2). This CRM can be used to prepare calibrant solutions and is applicable to national routine monitoring of DNT residuals in agro-products and food.

Simultaneous Determination of Neonicotinoid and Carbamate Pesticides in Freeze-Dried Cabbage by Modified QuEChERS and Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry.

Dehydrated vegetables are popular in instant foods, but few reports have focused on their pesticide residues. This research developed and validated a modified QuEChERS method combined with ultra-performance liquid chromatography-tandem mass spectrometry to determine 19 kinds of neonicotinoid and carbamate pesticides in freeze-dried cabbage. Herein, acetonitrile/water (v/v = 2:1) was selected in the extraction step. Meanwhile, 4 g anhydrous magnesium sulfate and 1 g sodium chloride were applied to the partitioning step. Dispersive solid-phase extraction sorbents were selected, and liquid chromatography conditions were further optimized for dealing with the matrix effect. The limits of quantification ranged from 1.0 to 10.0 µg/kg. The validation results were acceptable, with average recoveries of 78.7-114.0% and relative standard deviations below 14.2%. The method recoveries were closely related to the volume proportion of water in the extractant. Finally, the developed method was applied to real freeze-dried cabbages and four pesticides (propamocarb, imidacloprid, acetamiprid, and thiacloprid) were detected in six samples.

Chlorantraniliprole in foods: Determination, dissipation and decontamination.

Chlorantraniliprole (CAP) is the first commercially available anthranilic diamide insecticide that targets ryanodine receptors. However, excessive use of CAP can lead to persistent contamination on treated foods and adverse effects on human wellness. The current review focuses on CAP residue analysis in foods by using chromatographic techniques. QuEChERS (quick, easy, cheap, effective, rugged and safe) is the most widely used sample preparation strategy and liquid chromatography tandem mass spectrometry is the predominant analytical method for various food matrices including vegetable, fruit, grain, fish and so on. Moreover, this review summarizes the dissipation pattern of CAP on foods and found it usually dissipates fast on plant in open-field environment. For decontamination, common culinary cleaning methods could effectively remove CAP from vegetables. Finally, some new directions are proposed for better advancement.

Impurity Profiling of Dinotefuran by High Resolution Mass Spectrometry and SIRIUS Tool.

Dinotefuran (DNT) is a neonicotinoid insecticide widely used in pest control. Identification of structurally related impurities is indispensable during material purification and pesticide registration and certified reference material development, and therefore needs to be carefully characterized. In this study, a combined strategy with liquid chromatography high-resolution mass spectrometry and SIRIUS has been developed to elucidate impurities from DNT material. MS and MS/MS spectra were used to score the impurity candidates by isotope score and fragment tree in the computer assisted tool, SIRIUS. DNT, the main component, worked as an anchor for formula identification and impurity structure elucidation. With this strategy, two by-product impurities and one stereoisomer were identified. Their fragmentation pathways were concluded, and the mechanism for impurity formation was also proposed. This result showed a successful application for combined human intelligence and machine learning, in the identification of pesticide impurities.

Impurity identification in thiamethoxam by high resolution mass spectrometry and computer assisted elucidation.

Thiamethoxam (TMX) is a widely used neonicotinoid insecticide in pest control. Identification of structurally related impurities is very important during certified reference material development and pesticide registration, thus it needs to be carefully characterized. In this study, a combined strategy with liquid chromatography-high resolution mass spectrometry and computer assisted elucidation (SIRIUS) has been developed for the impurity elucidation in TMX material. MS and MS/MS spectra were used to score the impurity candidates by isotope score and fragment tree in SIRIUS. TMX, the main component, worked as an anchor for formula identification and structure elucidation of impurity. With this strategy, four impurities were identified, including two byproducts (TMX-OCH3 and TMX-Cl) and two metabolites (clothianidin and TMX-urea). Their fragmentation pathways were concluded, and mechanism of impurity formation was also proposed. This result showed successful application of combining human intelligence with machine learning in impurity identification from chemicals.

Maltose-functional metal-organic framework assisted laser desorption/ionization mass spectrometry for small biomolecule determination.

A series of functional metal-organic frameworks (MOFs) were facilely prepared through an one-pot procedure or post-synthetic modification strategy and used as matrices in laser desorption ionization mass spectrometry (LDI-MS). Compared with traditional organic matrices and other MOFs, maltose-functional MOF MIL-101-maltose demonstrated ultrahigh ionization efficiency, free matrix background, uniform crystallization, and good dispersibility. A simple, general, and efficient LDI-MS platform was developed for rapid detection of various small biomolecules using MIL-101-maltose as matrix, providing several advantages including low sample consumption of 500 nL, short analysis time of few seconds, strong salt tolerance (500 mM NaCl), and satisfactory reproducibility. The MIL-101-maltose matrix was used for serum glucose determination and successfully distinguished the diabetic patients from the healthy controls. This work provides a generic LDI-MS platform for fast determination of small biomolecules with high potential in clinical diagnosis and disease monitoring.

Determination of eight neonicotinoid insecticides in Chinese cabbage using a modified QuEChERS method combined with ultra performance liquid chromatography-tandem mass spectrometry.

A modified QuEChERS method was developed and combined with ultra performance liquid chromatography-tandem mass spectrometry to analyze eight neonicotinoid insecticides in Chinese cabbage. Herein, acetonitrile served as extraction solvent. Anhydrous sodium sulfate replaced the traditional anhydrous magnesium sulfate in the phase partition process to eliminate the influence of salt caking and heat release. Primary secondary amine and graphitized carbon black were selected as dispersive-solid phase extraction sorbents according to the clean-up efficiency evaluated by post-column infusion. The method showed good sensitivity with the limits of quantification below 1.0 µg/kg for eight analytes. The average recoveries ranged from 79.0% to 108.4% for three fortification levels, and the matrix effect could be ignored. For the tested samples, six neonicotinoids were detected, while cycloxaprid and imidaclothiz were not. The developed analytical method provided a powerful tool for monitoring neonicotinoid insecticides residues in Chinese cabbage.

Stability of a calibrant as certified reference material for determination of trans-zearalenone by high performance liquid chromatography-diode array detection-triple quadrupole tandem mass spectrometry.

In this study, a trans-zearalenone (trans-ZEN) calibrant in acetonitrile as certified reference material (CRM) was prepared and intensively investigated the stability by high performance liquid chromatography coupled diode array detection and triple quadrupole tandem mass spectrometry (HPLC-DAD-MS/MS). The photoisomerization and degradation of main component and related impurities in trans-ZEN calibrant CRM was studied in detail under different light conditions such as UV light (254 nm), sunlight, and visible light. Trans-ZEN in acetonitrile was confirmed a significant shift toward cis-ZEN up to a 52% cis-isomerization rate after exposing to UV light (254 nm) in transparent ampule for 1 day. The unsaturated double bond photosensitive groups of trans-ZEN and cis-ZEN will further undergo photoreaction to generate more isomers and related products with the increase of UV irradiation time. The calibrant in amber ampules was relatively stable after exposing to sunlight for 28 days, with only 0.35% cis-isomer observed. The results indicated that trans-ZEN solution calibrant should be packed in amber ampules to avoid UV rays. Thermal stability test exhibited this calibrant was stable over 6 weeks even at 60 °C. Trans-ZEN was found to be more stable in acetonitrile than in methanol since an unknown impurity was observed in methanol after 6 weeks placed at 25 °C. The stability study of trans-ZEN calibrant provided a basis for the usage, storage, and transportation of the CRM. A concentration and expanded uncertainty of the trans-ZEN calibrant CRM of 11.01 ± 0.18 µg/mL was developed.

Development of a Simple, Underivatized Method for Rapid Determination of Free Amino Acids in Honey Using Dilute-and-Shoot Strategy and Liquid Chromatography-Tandem Mass Spectrometry.

A simple, fast and reliable analytical method was developed for 20 free amino acids (FAAs) determination in honey samples through a dilute-and-shoot strategy and hydrophilic interaction liquid chromatography tandem mass spectrometry. Compared with previous reports, direct dilution by water has significantly reduced the matrix effect and facilitated full extraction of FAAs. Further, a 5 min determination method was established with an acetonitrile-water mobile phase system with 0.1% formic acid addition. The established method was validated and demonstrated several advantages including short detection time, wide linear range over 3-4 orders of magnitude, high sensitivity down to 0.1 ng/mL and negligible matrix effect. Twenty FAAs were determined in 10 honey samples from different botanical origins by this method, and 19 FAAs were found. This general applicable method was also promising for fast determination of FAAs in other practical samples.

Emulsification/demulsification method coupled to GC-MS/MS for analysis of multiclass pesticide residues in edible oils.

A simple, rapid, and sensitive method was developed for simultaneous determination of 103 multiclass pesticides in edible oils. A new strategy of sample preparation involving a spontaneous emulsification followed by membrane-based demulsification was proposed. The developed strategy was compared with other reputed clean-up procedures and found to improve the removal efficiency of matrix interferences without a significant loss of pesticides. GC-MS/MS was used to evaluate the proposed treatment methodologies. Recovery studies were performed at 10, 20, and 50 µg/kg levels in soybean oil, olive oil, and rapeseed oil. Throughout the validations, 70-120% overall recoveries were achieved with RSDs < 10% for the majority of pesticides. Limits of quantification ranged from 10 to 50 µg/kg (10 µg/kg for over 92% pesticides), less than the regulatory MRLs. Twenty-two of 30 market samples were found to contain one or several detectable pesticide residues ranged from < 1 to 105.9 µg/kg.

Recent progress in determination of ochratoxin a in foods by chromatographic and mass spectrometry methods.

Ochratoxin A is a highly toxic mycotoxin and has posed great threat to human health. Due to its serious toxicity and wide contamination, great efforts have been made to develop reliable determination methods. In this review, analytical methods are comprehensively summarized in terms of sample preparation strategy and instrumental analysis. Detailed method is described according to the food commodities in the order of cereal, wine, coffee, beer, cocoa, dried fruit and spice. This review mainly focuses on the recent advances, especially reported in the last decade. At last, challenges and perspectives are also discussed to achieve better advancement and promote practical application in this field.

Enrichment of diamide insecticides from environmental water samples using metal-organic frameworks as adsorbents for determination by liquid chromatography tandem mass spectrometry.

A series of metal-organic frameworks composed of different metal ions and organic linkers were facilely synthesized and used as adsorbents for five diamide insecticides for the first time. Among them, MIL-101-NH2 performed much better than other materials due to extraordinarily high specific surface area, strong water stability, specific interaction with analytes. A sensitive method was developed with MIL-101-NH2 based dispersive solid phase extraction combining with liquid chromatography tandem mass spectrometry (dSPE-LC-MS/MS). Important parameters including adsorbent amount, enrichment time, elution solvent and volume, pH and salt effect were investigated to achieve the best enrichment efficiency. At selected conditions, the proposed method showed ultrahigh sensitivity with limits of detection low to 0.01-0.03 ng/mL, which was 2-3 orders of magnitude lower than reported methods. Wide linearity in the range of 0.03-1000 ng/mL (chlorantraniliprole, cyantraniliprole) and 0.1-2000 ng/mL (flubendiamide, cyclaniliprole, tetrachlorantraniliprole) were established with satisfactory coefficient of determination. The method was successfully used for analyzing of diamide insecticides in environmental water samples and flubendiamide was detected in several samples. This work demonstrated the first example of developing novel nanomaterials in trace amount diamide insecticide enrichment from practical samples, which opens a new perspective in establishing nanomaterial-based sample preparation method for diamide insecticide analysis.

Nanostructured Substrates as Matrices for Surface Assisted Laser Desorption/Ionization Mass Spectrometry: A Progress Report from Material Research to Biomedical Applications.

Within the past two decades, the escalation of research output in nanotechnology fields has boosted the development of novel nanoparticles and nanostructured substrates for use as matrices in surface assisted laser desorption/ionization mass spectrometry (SALDI-MS). The application of nanomaterials as matrices, rather than organic matrices, offers remarkable characteristics that allow the analysis of small molecules with fewer matrix interfering peaks, and share higher detection sensitivity, specificity, and reproducibility. The technological advancement of SALDI-MS has in turn, propelled the application of the analytical technique in the field of biomedical analysis. In this review, the properties and fabrication methods of nanostructured substrates in SALDI-MS such as metallic-, carbon-, and silicon-based nanostructures, quantum dots, metal-organic frameworks, and covalent-organic frameworks are described. Additionally, the latest progress (most within 5 years) of biomedical applications in small molecule, large biomolecule, and MS imaging analysis including metabolite profiling, drug monitoring, bacteria identification, disease diagnosis, and therapeutic evaluation are demonstrated. Key parameters that govern nanomaterial's SALDI efficiency in biomolecule analysis are also discussed. Finally, perspectives of the future development are given to provide a better advancement and promote practical application in clinical MS.

The Occurrence and Contamination Level of Ochratoxin A in Plant and Animal-Derived Food Commodities.

Ochratoxin A (OTA) is a highly toxic mycotoxin and poses great threat to human health. Due to its serious toxicity and widespread contamination, great efforts have been made to evaluate its human exposure. This review focuses on the OTA occurrence and contamination level in nine plant and animal derived food commodities: cereal, wine, coffee, beer, cocoa, dried fruit, spice, meat, and milk. The occurrence and contamination level varied greatly in food commodities and were affected by many factors, including spices, geography, climate, and storage conditions. Therefore, risk monitoring must be routinely implemented to ensure minimal OTA intake and food safety.

Multiresponsive Tetra-Arylethene-Based Fluorescent Switch with Multicolored Changes: Single-Crystal Photochromism, Mechanochromism, and Acidichromism.

In this article, we report a simple tetra-arylethene-based fluorescent switch TPS═C4 modified with a flexible alkyl chain by the Schiff base structure. The incorporation of C═N retains the excellent photochromic property of tetra-arylethene and endows TPS═C4 with new multiresponsiveness of mechanochromism and acidichromism and multicolor changes. TPS═C4 shows remarkable mechanochromism from a deep blue emission at 420 nm to bright blue with a new shoulder band at 450 nm, which arises from the force-induced phase transition from the crystal state to an amorphous form. Both the original crystalline powder and the ground amorphous sample exhibit interesting acidichromism, and their emission colors turn yellow (530 nm), due to the protonation of C═N. More interestingly, TPS═C4 displays fascinating photochromism in multiple states, especially in the single-crystal state. The flexible alkyl chain offers enough free space for molecular motion and facilitates single-crystal photochromism. Due to the multiresponsiveness and multicolor switch, TPS═C4 can be satisfactorily used for the multidimensional anticounterfeiting application. To the best of our knowledge, TPS═C4 is a rare multifunctional molecule with a simple structure but featuring multiresponsiveness and multicolor switch.

Determination of patulin in apple juice by amine-functionalized solid-phase extraction coupled with isotope dilution liquid chromatography tandem mass spectrometry.

BACKGROUND: Patulin is a mycotoxin that mainly contaminates apple juice, which is a typical high sugar matrix. Many different adsorbents have been utilized to develop a sample pretreatment method to minimize the matrix interference from apple juice. RESULTS: A simple and reliable extraction method for the determination of patulin in apple juice has been developed. The sample preparation involves a simple one-step cleanup procedure using amine-functionalized polymeric solid-phase extraction cartridges (Retain AX) that effectively remove interferences and facilitate the quantification. Isotope dilution liquid chromatography tandem mass spectrometry (ID-LC-MS/MS) was employed to minimize the matrix effect and ensure reliable results. The limit of detection was as low as 0.2 µg kg-1 , which was satisfactory with regard to current European, US, and Chinese legislation. Matrix-matched linearity (r2 = 0.9997) was established in the range of 1-400 µg kg-1 . Recovery was performed in samples spiked at three levels, and results were between 97.2% and 100.2%. CONCLUSION: The results indicated that, with one-step cleanup, the matrix effect was negligible and sensitivity was satisfactory. Our work provided a simple and reliable method for patulin detection in apple juice and is also very promising in routine quality control. © 2020 Society of Chemical Industry.