Applications of Direct Injection Soft Chemical Ionisation-Mass Spectrometry for the Detection of Pre-blast Smokeless Powder Organic Additives

Analysis of smokeless powders is of interest from forensics and security perspectives. This article reports the detection of smokeless powder organic additives (in their pre-detonation condition), namely the stabiliser diphenylamine and its derivatives 2-nitrodiphenylamine and 4-nitrodiphenylamine, and the additives (used both as stabilisers and plasticisers) methyl centralite and ethyl centralite, by means of swab sampling followed by thermal desorption and direct injection soft chemical ionisation-mass spectrometry. Investigations on the product ions resulting from the reactions of the reagent ions H3O+ and O2+ with additives as a function of reduced electric field are reported. The method was comprehensively evaluated in terms of linearity, sensitivity and precision. For H3O+, the limits of detection (LoD) are in the range of 41-88 pg of additive, for which the accuracy varied between 1.5 and 3.2%, precision varied between 3.7 and 7.3% and linearity showed R20.9991. For O2+, LoD are in the range of 72 to 1.4 ng, with an accuracy of between 2.8 and 4.9% and a precision between 4.5 and 8.6% and R20.9914. The validated methodology was applied to the analysis of commercial pre-blast gun powders from different manufacturers.(VLID)4826148Accepted versio

Selective Reagent Ion Mass Spectrometric Investigations of the Nitroanilines

This paper presents an investigation of proton and charge transfer reactions to 2-, 3- and 4-nitroanilines (C6H6N2O2) involving the reagent ions H3O+·(H2O)n (n=0, 1 and 2) and O2+, respectively, as a function of reduced electric field (60-240 Td), using Selective Reagent Ion-Time-of-Flight-Mass Spectrometry (SRI-ToF-MS). To aid in the interpretation of the H3O+·(H2O)n experimental data, the proton affinities and gas-phase basicities for the three nitroaniline isomers have been determined using density functional theory. These calculations show that proton transfer from both the H3O+ and H3O+·H2O reagent ions to the nitroanilines will be exoergic and hence efficient, with the reactions proceeding at the collisional rate. For proton transfer from H3O+ to the NO2 sites, the exoergicities are 171 kJ mol-1 (1.8 eV), 147 kJ mol-1 (1.5 eV) and 194 kJ mol-1 (2.0 eV) for 2-, 3- and 4-nitroanilines, respectively. Electron transfer from all three of the nitroanilines is also significantly exothermic by approximately 4 eV. Although a substantial transfer of energy occurs during the ion/molecule reactions, the processes are found to predominantly proceed via non-dissociative pathways over a large reduced electric field range. Only at relatively high reduced electric fields (>180 Td) is dissociative proton and charge transfer observed. Differences in fragment product ions and their intensities provide a means to distinguish the isomers, with proton transfer distinguishing 2-nitroaniline (2-NA) from 3- and 4-NA, and charge transfer distinguishing 4-NA from 2- and 3-NA, thereby providing a means to enhance selectivity using SRI-ToF-MS.(VLID)4826158Version of recor

Evaluación del estado nutricional de los pacientes mayores atendidos en una unidad de hospitalización a domicilio Assessment of the nutritional status of elderly patients treated at a home-hospital unit

Objetivos: Establecer el estado nutricional de nuestros pacientes mayores, valorar la utilidad de los distintos parámetros antropométricos y bioquímicos como marcadores de desnutrición y determinar qué variables estudiadas tienen mayor correlación con la malnutrición. Ámbito: Unidad de Hospitalización a Domicilio del Hospital Universitario Arnau de Vilanova de Lleida. Pacientes: 57 pacientes &#8805; 60 años. Media de estancia en nuestra unidad: 12,1 días. Variables: Edad, sexo, grupos según la complejidad de las curas, patología asociada, diagnóstico, motivo de ingreso, tiempo de estancia hospitalaria, intervención quirúrgica practicada, complicaciones durante la estancia en la UHD, peso, talla, PCT, CB, IMC, CMB, albúmina, hemoglobina y RTL. Resultados: Los pacientes de "más edad" presentan una tasa de seroalbúmina (p Goals. To establish the nutritional status of our elderly patients, assess the usefulness of the various anthropometric and biochemical parameters as markers of malnutrition and to determine which of the variables studied have the greatest correlation with malnutrition. Scope: Home Hospital Unit of the Arnau de Vilanova Teaching Hospital in Lerida. Patients: 57 patients &#8805; 60 years. Mean admission to our unit: 12.1 days. Variables: Age, sex, groups by treatment complexity, associated pathology, diagnosis, reason for admission, duration of stay in hospital, surgery performed, complications during the stay at the Home Hospital Unit, weight, height, PCT, AC, BMI, albumin, haemoglobin and RTL. Results: Patients of great age present lower levels of serum albumin (p < 0.005), total proteins (p < 0.001), transferrin (p < 0.03), haemoglobin (p < 0.02) and RTL (p < 0.04) than "younger" elderly patients. Serum albumin and haemoglobin are lower in patients in a complicated post-surgical condition (p < 0.04 and p < 0.02, respectively) and this group is the one with the longest stays (p < 0.001). Those patients with hypoalbuminaemia (74.1%) present lower PCT and RTL (p < 0.02) and a longer stay in hospital (p < 0.01) than those with normal levels of albumin in blood. Patients with anaemia (63.3%) present a lower RTL (p < 0.01) and a greater hospitalization time than those without anaemia. Total proteins (p < 0.0001), albumin (p < 0.004), transferrin (p < 0.003) and RTL (p < 0.005) correlate negatively with age. Albumin (p < 0.001), haemoglobin (p < 0.006) and RTL (p < 0.0001) present a negative correlation with length of hospital stay. Conclusion: The prevalence of global malnutrition is high (51% moderate-severe). The nutritional status worsens with age. The length of hospitalization increases gradually with age, with deterioration in the nutritional status and with complexity of the treatment provided