We demonstrate a cost-effective UHPLC/CMS method for the analysis of chloramphenicol in milk with a detailed discussion of sensitivity, linear response range, carryover and robustness using the Advion expression® Compact Mass Spectrometer (CMS) and Advion AVANT™ UHPLC System.
This poster was presented at the 2019 ASMS Conference on Mass Spectrometry and Allied Topics in Atlanta, GA.
Federico II University Medical School of Naples, University of Naples “Federico II”
Vitamin D deficiency and obesity are two public health problems extensively exacerbated over the last years. Among the several mechanisms proposed to account for the complex interplay between vitamin D and obesity, one that has gained particular attention is related to the emerging role of obesity-related changes in gut microbiota and gut-derived metabolites, such as Trimethylamine-N-oxide (TMAO). Vitamin D deficiency and high circulating TMAO levels are associated with body weight and the severity of non-alcoholic fatty liver disease (NAFLD). Considering the link of obesity with vitamin D on the one hand and obesity with TMAO on the other hand, and the central role of the liver in both the vitamin D and TMAO metabolism, the aim of this cross-sectional observational study was first, to confirm the possible inverse association between vitamin D and TMAO across different body mass index (BMI) classes and second, to investigate if this association could be influenced by the presence of NAFLD. One hundred and four adult subjects (50 males and 54 females; 35.38 ± 7.49 years) were enrolled. The fatty liver index (FLI) was used as a proxy for the diagnosis of NAFLD. Vitamin D deficiency was found in 65 participants (62.5%), while 33 subjects (31.7%) had insufficient levels, and the remaining subjects had sufficient levels of vitamin D. Subjects with both vitamin D deficiency and FLI-NAFLD had the highest TMAO levels (p < 0.001). By stratifying the sample population according to the BMI classes, vitamin D levels decreased significantly along with the increase of plasma TMAO concentrations, with the lowest vitamin D levels and highest TMAO, respectively, in class III obesity. Vitamin D levels showed significant opposite associations with circulating levels of TMAO (r = −0.588, p < 0.001), but this association was no longer significant after the adjustment for FLI values. The highest values of TMAO were significantly associated with the severity of obesity (OR 7.92; p < 0.001), deficiency of vitamin D (OR 1.62; p< 0.001), and FLI-NAFLD (OR 3.79; p < 0.001). The most sensitive and specific cut-off for vitamin D to predict the circulating levels of TMAO was ≤19.83 ng/mL (p < 0.001). In conclusion, our study suggests that high TMAO levels are associated with vitamin D deficiency and NAFLD. Further studies are required to investigate if there is a causality link or whether all of them are simply the consequence of obesity.
Analysis was performed by LC/MS using the Advion expression® Compact Mass Spectrometer (CMS).
Nigerian Institute for Trypanosomiasis, University of Jos, University of Yaoundé
Medicinal plants are the richest bio-resource of drugs for traditional systems of medicine, modern medicines, food supplements, pharmaceutical intermediates and chemical entities for synthetic drugs. Human African Trypanosomiasis (HAT) is a challenging and deadly disease due to its complex epidemiology and clinical presentations. This study was conducted to investigate anti-trypanosomal action of Ximenia americana root bark on Trypanosoma brucei brucei using various solvent extracts and to develop thin layer (TLC-MS) and liquid chromatography-mass spectrometric (LC-MS) profiles of the plant. Soxhlet extraction was used to obtain acetone, 70% ethanol total extracts in addition to n-hexane, dichloromethane, ethyl acetate and methanol fractions by sequential extraction. The inhibitory activity of the various extracts was compared by testing against T. b. brucei using isometamidium chloride as standard drug. The most active extract was separated by solid-phase extraction (C18 stationary phase) to obtain fractions which were profiled by TLC-MS (+ESI) and LC-MS. It was observed that anti-trypanosomal activity of acetone (16.83% yield) and 70% ethanol (18.23% yield) were comparable. However, methanol extract exhibited the highest activity with 99.18%, 97.5% and 87.50% inhibition at 3 h incubation (room temperature) using 1000 µg, 500 µg and 250 µg concentrations respectively. The activities at 1000 µg for methanol extract and isometamidium chloride were comparable with 95% CI [-1.10, 1.77]. TLC-MS and LC-MS analyses suggested gallic acid, 2,3,4,5-tetrahydroxybenzoic acid, 2ʹ,5-dimethoxyflavone, quercetin, dihydroquercetin and sesquiterpene when compared with literature database. This study presents data that could be useful in standardisation and preparation of alternative medicine in the treatment of African trypanosomiasis.
Analysis was performed by TLC/MS using the Advion expression Compact Mass Spectrometer (CMS) and Plate Express TLC Plate Reader.
In this application note, the Advion Interchim Scientific® AVANT™ UHPLC/CMS system is used to analyze casein proteins in whole milk extract to separate and detect β-casein-B, -A1, and -A2, as well as K-casein and αs1-casein variants. This method is also suitable for a quick, relative quantitation of the β-casein-B, -A1, and -A2 variants in standards of β-casein.
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In this application note, a simple and cost-effective SIM LC/MS analytical approach employing the Advion expression Compact Mass Spectrometer (CMS) is described for the quantitation of 25-hydroxyvitamin D2 and D3 in human serum.
Merck & Co.
The evolution of supercritical fluid chromatography (SFC) instrumentation, improved detection capability, and expanded modifier range has led to extending the reach of SFC to the analysis of a broader spectrum of analytes beyond enantioselective separations. However, preparative SFC has yet to see the same technological revitalization, especially in regards to the purification of highly polar analytes. Enhanced fluidity liquid chromatography (EFLC) has been demonstrated as one of the ways to extend the applicable range of SFC instrumentation to highly polar analytes such as proteins, carbohydrates, and nucleotides. Despite recent applications of EFLC for challenging mixtures of hydrophilic metabolites and analogs, its viability in preparative purification, which is of great importance to the pharmaceutical industry, remains unknown. Herein, multiple chromatographic parameters that are critical to achieve feasible EFLC purification methods were investigated, including system pressure as a function of modifier composition (for several MeOH:H2O ratios), effect of diluent injection conditions on peak shape, and optimization of mass load with diluent composition. The usage of 50% acetonitrile or methanol diluents provided the most volumetric loading capacity. In the case of sucrose, leveraging higher analyte solubility in water proved to be more favorable than the volumetric loading capacity of diluents with higher organic content. In fact, an 80 mg injection of sucrose was possible on a 2 cm preparative HILIC column with minimal peak shape degradation. The combined information led to the successful demonstration of EFLC for the preparative separation of sugars using readily available MS-directed SFC instrumentation.
Reaction monitoring is a key aspect in a range of chemistry environments from chemical synthesis to drug discovery to understanding natural products to protein synthesis. Understanding the optimal time to quench a reaction for maximum yield, as well as monitoring a reaction in real-time is vital to many medicinal and synthetic organic chemists. Advion Interchim Scientific’s expression® CMS was developed with the chemist in mind to optimize their workflow directly at the bench. It is an easy-to-use and maintain single quadrupole detector that integrates with the industry’s broadest range of innovative sampling techniques from direct probe analysis to ultra-high performance liquid chromatography. Users can rapidly switch between the many different sampling techniques required throughout the chemist’s workflow.
We are the Institute for Therapeutics Discovery & Development. One of our main research core’s goals is the synthesis of biologically active small molecules with the additional goal of training the next generation of scientists through the Department of Medicinal Chemistry’s graduate student program. Our projects focus areas include contraception, cancer, infectious disease, and Alzheimer’s.
A major headache for any synthetic chemist is the identification of the desired product when a mixture is obtained from a reaction. In the past, we would typically run a flash chromatography column, isolate spots of potential interest, concentrate them, and take 1H NMR, sometimes having to go back to column fractions as many as 4 times to analyze new spots if the first wasn’t desired product.
Advion’s TLC–CMS system has streamlined our purification and analytical process significantly. What once took several hours to days to complete, we can now accomplish in as a little as 60 seconds. The Data Express software is also very easy to work with and has been quite useful in identifying adducts of our compounds.
We have been extremely happy with our Advion system and predict that it will quickly become a workhorse in any synthetic organic or medicinal chemistry laboratory.
University of Naples Federico II, Hospital Cardarelli, Coop. Samnium Medica, UCCP
Atherosclerotic cardiovascular diseases are preferential targets of healthy diet and preventive medicine partially through strategies to improve lipid profile and counteract oxidative metabolites. Ninety individuals with cardiovascular disease (CVD) risk factors were randomized (1:1:1 ratio) to three arms, according to a four-week run-in, eight-week intervention, and four-week follow up study, testing the effects of a lactofermented Annurca apple puree (lfAAP), compared to unfermented apple puree (AAP) or probiotic alone (LAB) on plasma lipid profile and trimethylamine-N-oxide (TMAO) levels. By comparing the treatments, data indicated for the subjects tested with lfAAP a higher variation of the following serum parameters, in respect to the other treatment groups: high density lipoprotein cholesterol (HDL-C), +61.8% (p = 0.0095); and TMAO levels, −63.1% (p = 0.0042). The present study would suggest lfAAP as an effective functional food for beneficial control of plasma HDL-C and TMAO levels.
HPLC-DAD/ESI-MS analysis using the Advion expression® Compact Mass Spectrometer (CMS) was used to quantify TMAO in blood samples.