Search results for " MS"
showing 10 items of 169 documents
Synthesis, Structural Analysis, Fiber Formation and Preliminary Anticancer Characterization of the Organotin Polyether from Dibutyltin Dichloride and…
2012
The organotin polyether derived from reaction of dibutyltin dichloride and 2,5-dimethyl-3-hexyne-2,5-diol was rapidly synthesized employing classical interfacial polymerization in 65% yield and a chain length of 360 units. IR results are consistent with the polyether structure. Bands characteristic of the formation of the Sn-O are present and bands characteristic of the Sn-Cl are absent. F MALDI MS results in the low mass range gives ion fragment clusters to five units. Isotopic abundance matches for tin are consistent with its presence in these ion fragment clusters. In the high mass range ion fragment clusters to greater than 300 units are found. The products offer outstanding inhibition …
Application of LA-ICP-MS as a rapid tool for analysis of elemental impurities in active pharmaceutical ingredients.
2014
The control of inorganic contaminants in active pharmaceutical ingredients has a significant role in the quality control of drug products. The concentration limits for metal residues in drug products have been defined by various regulatory guidelines. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is a powerful and fast analytical technique for multi-elemental analysis. A disadvantage in using LA-ICP-MS method is the lack of matrix reference materials for validation and calibration purposes. This article focuses on the handling strategy of laboratory-made matrix calibration standards for the quantification of elemental impurities in an active pharmaceutical ingredie…
Exposure of the Croatian adult population to acrylamide through bread and bakery products
2019
The aim of the present study was to determine and compare the levels of acrylamide in different types of bread and bakery products using a LC– MS/MS method, before and after the new European regulation on acrylamide reduction (Commission Regulation (EU) 2017/2158) became valid. Also, one of the aim was to estimate the average exposure to acrylamide through this food category. Of the total of 100 analysed samples, acrylamide content ranged from below the limit of quantification (LOQ) to 237 μg/kg in the period before the application of a new European Regulation, and from <LOQ to 42 μg/kg after it's application. For the adult Croatian population the dietary mean exposure to acrylamide in brea…
Mycotoxin Analysis of Human Urine by LC-MS/MS: A Comparative Extraction Study
2017
The lower mycotoxin levels detected in urine make the development of sensitive and accurate analytical methods essential. Three extraction methods, namely salting-out liquid–liquid extraction (SALLE), miniQuEChERS (quick, easy, cheap, effective, rugged, and safe), and dispersive liquid–liquid microextraction (DLLME), were evaluated and compared based on analytical parameters for the quantitative LC-MS/MS measurement of 11 mycotoxins (AFB1, AFB2, AFG1, AFG2, OTA, ZEA, BEA, EN A, EN B, EN A1 and EN B1) in human urine. DLLME was selected as the most appropriate methodology, as it produced better validation results for recovery (79–113%), reproducibility (RSDs < 12%), and repeatability (RSDs…
Colorectal cancer with microsatellite instability: Right-sided location and signet ring cell histology are associated with nodal metastases, and extr…
2021
Colorectal cancer (CRC) with microsatellite instability (MSI) accounts for 15-18 % of all CRCs and represents the category with the best prognosis. This study aimed at determining any possible clinical/pathological features associated with a higher risk of nodal metastasization in MSI-CRC, and at defining any possible prognostic moderators in this setting. All surgically resected CRCs of the last 20 years (mono-institutional series) with a PCR-based diagnosis of MSI, with and without nodal metastasis, have been retrieved for histological review, which was performed following WHO guidelines. Furthermore, the most important prognostic moderators have been investigated with a survival analysis…
Socio-Demographic Characteristics and Sexual Behavioral Factors of Patients with Sexually Transmitted Infections Attending a Hospital in Southern Ita…
2021
Sexually transmitted infections (STIs) are a serious global health problem. In Italy, data describing the vulnerability to STIs of specific sexual minorities and the influence of sociodemographic and behavioral determinants are limited, as most infections are not subject to mandatory notification. This retrospective study describes the sociodemographic profile and main sexual behaviors of patients attending a hospital in Palermo (Sicily, Italy) from January 2018 to March 2019 as predictors of STI risk. Patients were divided in subgroups: men-who-have-sex-with-men (MSM), men-who-have-sex-with-women (MSW), bisexual men and females. Data were obtained through an anonymous questionnaire. Patien…
Presence of mycotoxins in sorghum and intake estimation in Tunisia
2014
Sorghum samples (n = 60) from Tunisian markets were analysed for the occurrence of 22 of both traditional and emerging mycotoxins. Samples were extracted with a QuEChERS-like method and mycotoxins were detected by LC-MS/MS. This method was validated and adequate analytical parameters were obtained. All samples had contamination with mycotoxins and several samples had higher contamination levels than European Union legislative limits (MLs). The most frequently found mycotoxins were ENB (100%), OTA (98%), ENA₁ (63%), ENB₁ (56%), BEA (48%), AFB1 (38%) and STG (33%). Mean contaminations were 30.7, 1.93, 33.2, 51.0, 15.4, 1.49 and 20.5 µg kg(-1), respectively. While two samples were contaminated…
Supramolecular Aggregates in Vacuum: Positively Mono-Charged Sodium Alkanesulfonate Clusters
2010
The formation and structural features of positively mono-charged aggregates of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) and sodium methane—(MetS), butane—(ButS) and octane—(OctS) sulfonate molecules in the gas phase have been investigated by electrospray ionization mass spectrometry, energy-resolved mass spectrometry and density functional theory (DFT) calculations. The experimental results show that the center-of-mass collision energy required to dissociate 50% of these mono-charged aggregates scantly depends on the length of the alkyl chain as well as on the aggregation number. This, together with the large predominance of mono-charged species in the mass spectra, was rationalized i…
Mycotoxin contamination in laboratory rat feeds and their implications in animal research
2016
Compound feed is particularly vulnerable to multi-mycotoxin contamination. A method for the determination of 12 mycotoxins; enniatins A, A1, B, B1; aflatoxins B1, B2, G1, G2; OTA; ZEA; T-2 and HT-2 by liquid chromatography-tandem mass spectrometry has been developed and applied for the analysis of laboratory rat commercial feeds. The method trueness was checked by recovery assays at three different spiked levels (n = 9). Recoveries ranged from 73% to 112%, and the intra-day and inter-day precision were lower than 9% and 13%, respectively. Limits of quantitation were lower than 15 μg/kg. Twenty-seven laboratory rats feed samples showed multi-contamination by at least three up to six differen…
Phenolic profile of oils obtained from “horchata” by-products assisted by supercritical-CO2 and its relationship with antioxidant and lipid oxidation…
2019
Abstract In this study, the effect of different supercritical CO 2 (SC-CO 2 ) pressures (10–40 MPa) on phenolic compounds extraction in oils obtained from “ horchata ” by-products was evaluated, and the results were compared to those obtained after conventional oil extraction (CE). Moreover, the relationship between the individual phenolic compounds and the total antioxidant capacity as well as oil oxidative quality parameters was compared. The phenolic profile and contents were largely influenced by extracting conditions. The main phenolic compound obtained by SC-CO 2 was the isohydroxymatairesinol, particularly at 30 and 40 MPa, while 3-vinylphenol was the predominant compound in oils ext…