A symbolic Neanderthal accumulation of large herbivore crania.

This work examines the possible behaviour of Neanderthal groups at the Cueva Des-Cubierta (central Spain) via the analysis of the latter's archaeological assemblage. Alongside evidence of Mousterian lithic industry, Level 3 of the cave infill was found to contain an assemblage of mammalian bone remains dominated by the crania of large ungulates, some associated with small hearths. The scarcity of post-cranial elements, teeth, mandibles and maxillae, along with evidence of anthropogenic modification of the crania (cut and percussion marks), indicates that the carcasses of the corresponding animals were initially processed outside the cave, and the crania were later brought inside. A second round of processing then took place, possibly related to the removal of the brain. The continued presence of crania throughout Level 3 indicates that this behaviour was recurrent during this level's formation. This behaviour seems to have no subsistence-related purpose but to be more symbolic in its intent.

Determination study of contaminants of emerging concern at trace levels in agricultural soil. A pilot study.

In this study, we aimed to develop and validate a quick, easy, and robust extraction method for the simultaneous determination of 30 organic contaminants of emerging concern (CECs) including some transformation products in soil samples. Three different extraction methods based on an ultrasonic cylindrical probe (UAE), a pressurized liquid extraction (PLE), and a QuEChERS method were compared. Ultra-performance liquid chromatography coupled with electrospray tandem mass spectrometry (LC-MS/MS) was used for identification and quantification of the target analytes. A modified QuEChERS method showed the best results in terms of extractability and accuracy. The extraction procedure developed provided adequate extraction performances (70% of the target analytes were recovered within a 70-99% range), with good repeatability and reproducibility (variations below 20%) and great sensitivity (LOQ < 0.1 ng/g in most cases). No matrix effects were observed for 70% of the compounds. Finally, the analytical methodology was applied in a pilot study where agricultural soil was irrigated with reclaimed water spiked with the contaminants under study. Of the 25 CECs added in irrigation water, a total of 13 pesticides and 5 pharmaceutical products were detected at concentration ranges from 0.1 to 1.2 ng/g (d.w) and from 0.1 to 2.0 ng/g (d.w), respectively.

Solid phase extraction of pesticides from environmental waters using an MSU-1 mesoporous material and determination by UPLC-MS/MS.

This paper describes the synthesis of a silica based MSU-1 mesoporous solid and its application as sorbent in solid-phase extraction to pre-concentrate thirteen pesticides of low-high polarity (methomyl, cymoxanil, carbofuran, monolinuron, isoproturon, methidathion, methiocarb, malathion, phosalone, diazinon, penconazole, neburon and chlorotoluron) in ground and river water. The synthesis was based in an H-bonding interaction assembling (I0N0) between two non-ionic components (the inorganic silica surface, I0 and the polyethylene oxide template, N0) by adding tetraethoxysilane to the non-ionic surfactant Brij®100, the latter previously dissolved in HCl 1 M. 50 mL water samples adjusted at pH= 3.5 were passed, at a flow rate of 5 mL/min, through a home-made cartridge containing 50 mg of MSU-1 sorbent, pre-conditioned with 5 mL of ultrapure water; then, the cartridge was washed with 5 mL of ultrapure water. Following elution with 5 mL of acetonitrile, the pesticides were determined by ultra performance liquid chromatography coupled to triple quadrupole-mass spectrometry. Two selected reaction monitoring transitions were monitored per compound, the most intense one being used for quantification and the second one for confirmation. Three points were used for identification, as established in the Directive 96/23/EC for LC-MS/MS analysis, which deals with confirmatory methods for organic residues and contaminants listed in the Group B (veterinary drugs and contaminants). Medium matrix effect (|20%||50%|). Therefore, the standard addition methodology was applied by adding an adequate amount of the pesticide standard mixture to the final sample extract. All pesticides were quantified using this approach for practical reasons, thus avoiding two different calibrations. The method quantification limit (MQL) of pesticides was 0.01 µg/L for all of them, except for diazinon (0.1 µg/L). Recoveries of the target pesticides at MQL and 0.25 µg/L concentration levels in blank river water were in the range 70.1-113.5% and 86.7-107.3%, respectively, with RSDs lower than 16.3% and 15.7%, respectively. Four ground water samples and three river water samples, taken from Almería (Spain), were analyzed by the proposed method and only phosalone at a concentration level of 0.05 µg/L was found in one river water sample.

Desarrollo de un método de detección de Ocratoxina A (OTA) mediante Cromatografía Líquida de Alta Resolución con Detector de Masas en Tiempo de Vuelo / Development of a method for the Ochratoxin A (OTA) detection by High Resolution Liquid Chromatography with Time Mass Detector

Antecedentes: La ocratoxina A (OTA) es una micotoxina producida por algunos hongos (Aspergillus y Penicillium). Puede aparecer en diversos alimentos dependiendo de las condiciones de producción y almacenamiento. Presenta propiedades carcinógenas, nefrotóxicas, teratógenas, inmunotóxicas y neurotóxicas. Es tóxica por inhalación y por ingestión, presenta una elevada estabilidad y su obtención es relativamente sencilla, pudiendo representar un serio problema de salud pública y seguridad. Por ello existe la necesidad de desarrollar métodos de detección rápidos y específicos, que contribuyan a garantizar la seguridad de los ciudadanos. En este sentido, la cromatografía líquida acoplada a un detector de masas de tiempo de vuelo (HPLC-MSD (TOF)) se revela como una técnica diagnóstica muy adecuada para conseguir una detección rápida y específica de dicha micotoxina. Objetivo: Desarrollo de un método de detección de OTA, rápido y específico mediante HPLC-MSD (TOF). Material y Métodos: Se realizaron 36 ensayos con diferentes condiciones cromatográficas y espectrométricas. En todos los casos se utilizó un HPLC 1200 y un MSD-TOF 6210, con fuente de ionización electrospray (Agilent Technologies). Resultados: El cromatograma obtenido mostró el pico de OTA a un tiempo de retención de 1,791 ± 0,009 minutos. En su espectro de masas se observa el ion molecular [M+H]+ a 404,07986 uma y su perfil isotópico característico. Conclusiones: El método optimizado mediante HPLC-MSD (TOF) para la detección de OTA es rápido y específico. Este método podría ser adecuado para la detección de otras toxinas, permitiendo crear una base de datos para toxinas susceptibles de ser utilizadas como agentes bioterroristas

Antecedents: Ochratoxin A (OTA) is a mycotoxin produced by some fungi (Aspergillus y Penicillium). It can be found in several types of food, depending on both production and storage conditions. It has carcinogenic, nephrotoxic, teratogenic, immunotoxic and neurotoxic properties. It is toxic by inhalation and by ingestion. Since this toxin has a high stability and its extraction is relatively simple, it represents a serious public health and safety problem. Therefore, in order to help ensure the safety of all the citizens, it is necessary to develop a fast and sensitive ochratoxin detection method. In this sense, liquid chromatography coupled to a time-of-flight mass detector (HPLC-MSD (TOF)) is revealed as a very suitable diagnostic technique to achieve a rapid and specific detection of this mycotoxin. Aim: Development of a fast and specific method of OTA using HPLCMSD (TOF). Material and Methods: Thirty-six assays were tested with different chromatographic and spectrometric conditions. In all the assayed cases, HPLC 1200 and an MSD (TOF) 6210 with electrospray ionization source were used, (Agilent Technologies). Results: The chromatogram obtained showed the peak of OTA at a retention time of 1,791 ± 0,009 minutes. In its mass spectrum it is observed both the molecular ion [M+H]+ at 404,07986 uma and its characteristic isotopic profile. Conclusions: The OTA detection method optimized by HPLC-MSD (TOF) is fast and specific. This method could be suitable for the detection of other toxins, allowing the creation of a database for toxins suspected of being used as bioterrorist agents (or biological warfare agents)

Simulacro de Actuación de las Unidades Operativas NRBQ / Training exercise of CBN Operating Units

Antecedentes: Ante la creciente amenaza terrorista, la mayoría de los países han creado Unidades Operativas especializadas en la lucha contra armas de destrucción masiva (ADM). Uno de los puntos críticos en un incidente bioterrorista es la detección e identificación precoz de estos agentes, para lo cual es imprescindible realizar una adecuada toma de muestras, conservación, transporte y custodia de las mismas hasta el laboratorio de referencia. Objetivo: Valorar el entrenamiento de las Unidades de toma de muestras NBQ mediante la realización de simulacros. Lugar de realización: Área de Defensa Biológica del Instituto Nacional de Técnica Aeroespacial «Esteban Terradas» (INTA). Diseño: Se presenta la preparación y desarrollo de un ejercicio de entrenamiento de los Equipos de Reconocimiento (RECO) y de Muestreo e Identificación de Agentes Biológicos, Químicos y Radiológicos (SIBCRA en inglés) del Regimiento de la Defensa NBQ Valencia I (RGTO DNBQ Valencia I). Resultados: Se obtienen muestras NBQ y se evalúa la eficacia de la operativa de la toma de muestras, transmisión de los datos y coordinación general del ejercicio (AU)

Antecedents: Due to the merging terrorist threat, most of the countries have created specialized operating units to fight weapons of mass destruction. One of the critical points in a bioterrorist incident is the early detection and identification of these agents. In this sense, it is essential to perform appropriate procedures for sampling, storage, transportation and custody of them until the reference laboratory. Objective: to train the different NBC Units by means of simulacrums. Place of performance: Biological Defense Area of the National Institute of Aerospace Technique "Esteban Terradas" (INTA). Design: This paper shows the preparation and development of a training exercise of Reconnaissance teams (RECO) and Sampling and Identification of Biological, Chemical and Radiological Agents teams (SIBCRA) from NBC Defense Regiment Valencia I. Results: NBQ samples are obtained and the efficiency of the operations, sampling, data transmission and general coordination of the exercise is evaluated (AU)

Validation and incidence of community-acquired pneumonia in patients with type 2 diabetes in the BIFAP database.

Oral anti-diabetic drugs (OADs) have been associated with community-acquired pneumonia (CAP). We aimed to validate the recording of CAP in the Spanish Database for Pharmacoepidemiological Research in Primary Care (BIFAP) for the future evaluation of OAD-CAP association. The incidence rate (IR/1000 person-years) of CAP in type 2 diabetes mellitus (T2DM) was also determined. In total, 2966 pneumonia records (2040 listed as diagnosis and 926 as identified from comments added by physicians) were identified from 76 009 patients with T2DM after the first OAD in 2002-2013. Data around the CAP date were reviewed: 1803 (60·9%) were classified as 'probable CAP' (confirmed by X-ray/laboratory, referral letters or CAP lung site); 589 (19·8%) as 'no-case' (486 had other illness, 78 previous CAP, 25 cancer); and 574 (19·4%) as 'possible CAP' (441 without confirmatory information, 133 with uncertain diagnosis or uncertain diagnosis date). In total, 74·2% and 31·4% of pneumonia records in the diagnosis and comments, respectively, were 'probable cases' (IR: 6·04), which increased to 90·5% and 42·9%, respectively, when the 441 'possible cases' without confirmatory information were included (IR: 7·52). In summary, diagnosis had a high positive predictive value, and adding cases automatically detected from comments decreased that value significantly.

Protocolo para la identificación rápida y sensible de ricina en muestras ambientales ante una alerta biológica / Protocol for rapid and sensitive identification of ricin in environmental samples during a biological alert

Introducción: La ricina es una toxina muy potente que ha adquirido importancia por su potencial uso como arma biológica, fundamentalmente en forma pulverulenta. El desarrollo de métodos que permitan una detección rápida y temprana tras la exposición a la toxina permitiría reducir las tasas de morbilidad y mortalidad asociadas. Ante una alerta/amenaza biológica con una muestra sospechosa de contener ricina, la Red de Laboratorios de Alerta Biológica (RELAB), infraestructura de naturaleza científico-técnica creada mediante la Orden PRE/305/2009, autoriza el envío de la muestra al Instituto Nacional de Técnica Aerospacial (INTA), uno de los laboratorios de referencia que integran esta Red. Objetivos: Desarrollo de un protocolo para la detección de ricina basado en una doble detección, un ensayo inmunológico y un análisis proteico, para aumentar la fiabilidad del diagnóstico además de acortar sensiblemente el tiempo de respuesta del laboratorio. Material y Métodos: El diagnóstico inmunológico con anticuerpos in house combinados en un ELISA tipo Sandwich. El diagnóstico proteico mediante la técnica SDS-PAGE (electroforesis en gel de poliacrilamida con dodecilsulfato sódico) para determinar el tamaño y la estructura de las distintas proteínas de la muestra. Resultados: La optimización del marcado de los anticuerpos de detección, así como la preparación y almacenamiento de placas previamente tapizadas/bloqueadas permite conseguir un ensayo muy sensible (<1 ng/mL) en un tiempo inferior a cuatro horas. Conclusión: La realización de ambos ensayos en paralelo permite disponer de un método diagnóstico robusto, sensible y rápido (AU)

Introduction: Ricin is a powerful toxin wich has gained importance due to its potential use as biological weapon, essentially in powder form. The development of methods that promote a rapid detection after the toxin exposure will allow us to reduce its associated rates of both mobility and mortality. In the face of biological threat with samples suspected of containing ricin, the Biological-Alert-Laboratory-Network (RELAB), which is a scientific-technical infrastructure created by the Order of the Ministry of the Presidency PRE/305/2009, authorizes the shipment of this type of samples to the National Institute of Aerospace Technique (INTA), one of the Reference Laboratory belonging to this Network. Aim: Development of one protocol to detect ricin based on both an immunological assay and a protein analysis focused to reduce noticeably the response time of the laboratory. Material and Methods: The Immunological diagnosis of ricin uses in house antibodies combined in an ELISA sandwich. Protein diagnosis through the SDS-PAGE technique defines the size and structure of different proteins contained in the sample. Results: The optimization of detection antibody labelling and the development of precoated-and-preblocked stored plates has allowed us to achieve a very sensitive assay (<1 ng/mL) less than four hours. Conclusion: Carrying out both assays in paralell enables us to have a hardy, sensitive and rapid method to identify ricin (AU)

Mesoporous silica based MCM-41 as solid-phase extraction sorbent combined with micro-liquid chromatography-quadrupole-mass spectrometry for the analysis of pharmaceuticals in waters.

This paper reports the first application of the silica based mesoporous material MCM-41 as a sorbent in solid phase extraction, to pre-concentrate pharmaceuticals of very different polarity (atenolol, nadolol, pindolol, timolol, bisoprolol, metoprolol, betaxolol, ketoprofen, naproxen, ibuprofen, diclofenac, tolfenamic acid, flufenamic acid and meclofenamic acid) in surface waters. The analytes were extracted from 100mL water samples at pH 2.0 (containing 10(-3) mol/L of sodium chloride) by passing the solution through a cartridge filled with 100 mg of MCM-41. Following elution, the pharmaceuticals were determined by micro-liquid chromatography and triple quadrupole-mass spectrometry. Two selected reaction monitoring transitions were monitored per compound, the most intense one being used for quantification and the second one for confirmation. Matrix effect was found in real waters for most analytes and was overcome using the standard addition method, which compared favorably with the matrix matched calibration method. The detection limits in solvent (acetonitrile:water 10:90, v/v) ranged from 0.01 to 1.48 µg/L and in real water extracts from 0.10 to 3.85 µg/L (0.001-0.0385 µg/L in the water samples). The quantitation limits in solvent were in the range 0.02-4.93 µg/L, whereas in real water extracts were between 0.45 and 10.00 µg/L (0.0045 and 0.1000 µg/L in the water samples). When ultrapure water samples were spiked at two concentration levels of each pharmaceutical (0.1 and 0.2 µg/L) and quantified using solvent based calibration graphs, recoveries were near 100%. However, recoveries for most pharmaceuticals were comparable or better than de described above, when river water samples (spiked at the same concentration levels) were quantified by the standard addition method and slightly worse using the matrix matched calibration method. Five real samples (two rivers, one dam and two fountain water samples) were analyzed by the developed method, atenolol, timolol, betaxolol, nadolol and diclofenac being found in some of them, at levels higher than their quantitation limits.

Determination of drugs in river and wastewaters using solid-phase extraction by packed multi-walled carbon nanotubes and liquid chromatography-quadrupole-linear ion trap-mass spectrometry.

The present paper describes a solid-phase extraction by packed multi-walled carbon nanotubes, followed by liquid chromatography-mass spectrometry, method for the determination of some of the most consumed drugs including four ß-blockers and eight non-steroidal anti-inflammatory drugs, in river and wastewater samples. High extraction efficiency was found for most drugs due to the large specific surface area and high adsorption capacity of this nanomaterial compared with other conventional solid-phase extraction sorbents, and matrix effect was present only for two of the twelve studied drugs. Only 20mg of carbon nanotubes was enough to preconcentrate the analytes with recoveries from 68% to 107% for most of them. The pharmaceuticals were analyzed by liquid chromatography coupled to a hybrid triple quadrupole-linear ion trap-mass spectrometer at ultra-trace levels. Data acquisition was carried out in selected reaction monitoring mode, using two transitions for simultaneous identification and quantification of the analytes. Additionally, an information dependent acquisition scan was performed to carry out the identification of those analytes whose second transition was absent or was present at low intensity. The analytical performance of the whole method was evaluated in two environmental water matrices (river and wastewaters). Matrix effect was not found in river water, quantitation being carried out with calibration graphs built with solvent based standard. On the contrary, matrix effect was present in wastewater for some of the target drugs and, therefore, quantitation was carried out using the standard addition method. Limits of detection and quantitation in river waters were in the range of 9-36 and 23-121ngL(-1), respectively and the relative standard deviation of the full method was less than 17%. The proposed methodology was applied to the analysis of three river water and two wastewater (influent and effluent) samples, all of them from Almería (Spain). Some pharmaceuticals were found in river water at concentration levels near to or lower than their quantitation limits, whereas the most consumed pharmaceuticals were found at high concentration levels in influent wastewater and were not detected or were found at lower levels in the effluent wastewater sample.

Ultrasound-assisted ionic liquid dispersive liquid-liquid microextraction coupled with liquid chromatography-quadrupole-linear ion trap-mass spectrometry for simultaneous analysis of pharmaceuticals in wastewaters.

A simple, rapid, low environmental toxicity and sensitive ultrasound-assisted ionic liquid dispersive liquid-liquid microextraction (US-IL-DLLME) procedure was developed for the extraction of nine pharmaceuticals (paracetamol, metoprolol, bisoprolol, betaxolol, ketoprofen, naproxen, ibuprofen, flufenamic acid and tolfenamic acid) in wastewater, and their determination using high-performance liquid chromatography with a hybrid triple quadrupole-linear ion trap-mass spectrometer (LC-QqLIT-MS). The IL 1-octyl-3-methylimidazolium hexafluorophosphate ([C8MIM][PF6]) and acetonitrile (ACN) were used as extraction and disperser solvent, respectively, for the DLLME procedure, instead of using toxic chlorinated solvent. The factors affecting the extraction efficiency, such as the type and volume of ionic liquid, type and volume of disperser solvent, cooling in ice-water, sonication time, centrifuging time, sample pH and ionic strength, were optimized. The ultrasound-assisted process was applied to accelerate the formation of the fine cloudy solution using a small volume of disperser solvent (0.5mL of acetonitrile), which increased the extraction efficiency and reduced the equilibrium time. A slight increase in the recoveries of pharmaceuticals was observed when an ice-water bath extraction step was included in the analytical procedure. In this way, enrichment factors between 255 and 340 were obtained. Data acquisition in selected reaction monitoring mode (SRM), allowed the simultaneous identification and quantification of the analytes using two transitions (SRM1 and SRM2). Additionally, the information dependent acquisition (IDA) scan was performed to carry out the identification of those analytes whose second transition was absent or was present at low intensity, also providing extra confirmation for the other analytes. The optimized US-IL-DLLME-LC-QqLIT-MS method showed a good precision level, with relative standard deviation values between 1.1% and 11.3%. Limits of detection and quantification were in the range 0.2-60ngL(-1) and 1.0-142ngL(-1), respectively. Good enrichment factors (255-340) and recoveries (88-111%) were obtained for the extraction of the target analytes in wastewater samples. This method has been successfully applied to analyze effluent wastewater samples from a municipal wastewater treatment plant located in Almería (Spain) and the results indicated the presence of flufenamic acid and metoprolol in concentration levels of 0.1 and 1.3µgL(-1), respectively.

Prediction of the processing factor for pesticides in apple juice by principal component analysis and multiple linear regression.

The main objective of this work was to establish a mathematical function that correlates pesticide residue levels in apple juice with the levels of the pesticides applied on the raw fruit, taking into account some of their physicochemical properties such as water solubility, the octanol/water partition coefficient, the organic carbon partition coefficient, vapour pressure and density. A mixture of 12 pesticides was applied to an apple tree; apples were collected after 10 days of application. After harvest, apples were treated with a mixture of three post-harvest pesticides and the fruits were then processed in order to obtain apple juice following a routine industrial process. The pesticide residue levels in the apple samples were analysed using two multi-residue methods based on LC-MS/MS and GC-MS/MS. The concentration of pesticides was determined in samples derived from the different steps of processing. The processing factors (the coefficient between residue level in the processed commodity and the residue level in the commodity to be processed) obtained for the full juicing process were found to vary among the different pesticides studied. In order to investigate the relationships between the levels of pesticide residue found in apple juice samples and their physicochemical properties, principal component analysis (PCA) was performed using two sets of samples (one of them using experimental data obtained in this work and the other including the data taken from the literature). In both cases the correlation was found between processing factors of pesticides in the apple juice and the negative logarithms (base 10) of the water solubility, octanol/water partition coefficient and organic carbon partition coefficient. The linear correlation between these physicochemical properties and the processing factor were established using a multiple linear regression technique.

Determination of pharmaceuticals in river water by column switching of large sample volumes and liquid chromatography-diode array detection, assisted by chemometrics: an integrated approach to green analytical methodologies.

An analytical method for the simultaneous determination of nine beta-blockers (sotalol atenolol, nadolol, pindolol, metoprolol, timolol, bisoprolol, propanolol and betaxolol) and two analgesics (paracetamol and phenazone) in river water by liquid chromatography and diode array detection is reported. The method involves a modified precolumn switching methodology replacing the small precolumn with a short C18 liquid chromatography column (50 mm x 4.6 mm, 5 microm particle size), thus allowing the preconcentration of large water sample volumes whereas interferences eluting at the first of the chromatogram were discarded to waste. This approach allowed to preconcentrate 30 mL river water samples, modified with 0.4% MeOH, achieving univariate method detection and determination limits ranged between 0.03 and 0.16 microg L(-1) and between 0.2 and 0.5 microg L(-1), respectively, with precision values lower than 9.4% for spiking levels at the quantitation limits of each analyte and lower than 4.0%, except bisoprolol (8.3%), for higher spiking levels (1.0 microg L(-1) of all analytes). Matrix background was reduced in three way data by a baseline correction following the Eilers methodology, whereas multivariate curve resolution and alternating least squares in combination with the standard addition calibration method, applied to these data, coped with overlapping peak, systematic (additive) and proportional (matrix effect) errors. The method was successfully applied for the determination of the target pharmaceuticals in river water from three places in a river stream with acceptable recoveries and precision values, taking into account the complexity of the analytical problem. The joint statistical test for the slope and the intercept of the linear regression between the nominal concentration values versus those predicted, showed that the region computed contained the theoretically expected values (0) for the intercept and (1) for the slope (at a confidence level of 95%), which indicates the absence of both constant and proportional errors in the predicted concentrations.

Chemometric tools improving the determination of anti-inflammatory and antiepileptic drugs in river and wastewater by solid-phase microextraction and liquid chromatography diode array detection.

An analytical method for the simultaneous determination of seven non-steroidal anti-inflammatory drugs (naproxen, ketoprofen, diclofenac, piroxicam, indomethacin, sulindac and diflunisal) and the anticonvulsant carbamazepine in river and wastewater is reported. The method involves pre-concentration and clean-up by solid-phase microextraction using polydimethylsiloxane/divinylbenzene fibers, followed by liquid chromatography with diode array detection analysis. Owing to the fact that river water samples did not contain interferences and no sensitivity changes due to sample matrix were observed, external calibration was implemented. Standardization was also applied in order to carry out the prediction step by preparing only two diluted standards that were subjected to the pre-concentration step and a set of standards prepared in solvent. For the analysis of wastewater samples, in contrast, it was necessary to implement standard addition calibration in combination with the multivariate curve resolution-alternating least squares (MCR-ALS) algorithm, which allowed us to overcome matrix effect and exploit the second order advantage. Recoveries ranging from 72% to 125% for all pharmaceuticals proved the accuracy of the proposed method in river water samples. On the other hand, wastewater sample recoveries ranged from 83% to 140% for all pharmaceuticals, showing an acceptable performance - considering this sample contains no modeled interferences.

Chemometric assisted solid-phase microextraction for the determination of anti-inflammatory and antiepileptic drugs in river water by liquid chromatography-diode array detection.

In the present work, an analytical method for the simultaneous determination of seven non steroidal anti-inflammatory drugs (naproxen, ketoprofen, diclofenac, piroxicam, indomethacin, sulindac and diflunisal) and the anticonvulsant carbamazepine is reported. The method involves preconcentration and clean-up by solid-phase microextraction using polydimethylsiloxane/divinylbenzene fibers, followed by liquid chromatography with diode array detection analysis. Parameters that affect the efficiency of the solid-phase microextraction step such as soaking solvent, soaking period, desorption period, stirring rate, extraction time, sample pH, ionic strength, organic solvent and temperature were investigated using a Plackett-Burman screening design. Then, the factors presenting significant positive effects on the analytical response (soaking period, stirring rate, stirring time) were considered in a further central composite design to optimize the operational conditions for the solid phase microextraction procedure. Additionally, multiple response simultaneous optimization by using the desirability function was used to find the optimum experimental conditions for the on-line solid-phase microextraction of analytes in river water samples coupled to liquid chromatography and diode array detection. The best results were obtained using a soaking period of 5 min, stirring rate of 1400 rpm and stirring time of 44 min. The use of solid-phase microextraction technique avoided matrix effect and allowed to quantify the analytes in river water samples by using Milli-Q based calibration graphs. Recoveries ranging from 71.6% to 122.8% for all pharmaceuticals proved the accuracy of the proposed method in river water samples. Method detection limits were in the range of 0.5-3.0 microgL(-1) and limits of quantitation (LOQs) were between 1.0 and 4.0 microgL(-1) for pharmaceutical compounds in river water samples. The expanded uncertainty associated to the measurement of the concentration ranged between 8.5% and 29.0% for 20 microgL(-1) of each analyte and between 9.0% and 29.5% for the average of different concentration levels. The main source of uncertainty was the calibration step in both cases.

Análisis de la actividad de una Unidad de Cuidados Intermedios Respiratorios en Madrid / Analysis of the activity of an Intermediate Respiratory Care Unit in Madrid

El objetivo del presente análisis es comparar retrospectivamente el número de pacientes y sus características ingresados en una unidad de cuidados intermedios respiratorios (UCIR) en un hospital terciario antes y después de su dotación en equipos de elevadas prestaciones y personal. Para ello se comparó el número de ingresos, exitus e intubaciones así como la gravedad de los sujetos al ingreso, su estancia media, los parámetros ventilatorios utilizados y su origen entre los meses de enero y diciembre de 2007 con respecto a años previos. Se detectó que el número de ingresos dobló al de años anteriores. La gravedad de los pacientes ingresados era mayor y sin embargo se redujo notablemente la mortalidad y la estancia media. Globalmente aumentó la demanda entre los diferentes servicios del hospital. Los parámetros ventilatorios fueron sensiblemente menos agresivos. En conclusión, la dotación de equipos de altas prestaciones y un personal dedicado y especializado en ventilación mecánica no invasiva son vitales para implementar la eficacia de la unidad (AU)

The main objective of the present paper is to analyze in a retrospecive manner the number and characteristics of patients admitted to our Intermediate Respiratory Unit before and after the installation of new equipment and staff specially dedicated to non invasive ventilation treatment. We performed a comparison of the number of admittance, mortality and intubation rates, source of patients, ventilatory settings, severity scores, mean stay between January to 1st September 2007 compared to same period of previous years. We observed that in 2007 we received the double of admittances, patients were more severe but mortality rates, mean stay were lower. The ventilatory settings were in this 2007 period less aggressive than previously. As a conclusion, to improve our respiratory intermediate units specialized equipment and staff are critical (AU)

Application of the Doehlert design to optimize the signal obtained in photochemically induced fluorescence for the determination of eight phenylureas.

This work describes the optimization of a photochemically induced method for the detection of eight phenylureas has been developed by response surface methodology (RSM). These pesticides do not show native fluorescence but they were photolyzed into strongly fluorescent photoproducts under UV irradiation. The effect of the main variables affecting the yield of the photoderivatization reaction, and hence the fluorescence intensity, such as solvent, UV irradiation time and pH were optimized for each pesticide. A Doehlert design was applied in order to obtain maximum intensity fluorescence using response surface methodology. In general, a maximum was found for all pesticides using MeOH as organic solvent, except for diuron, whereas the effect of pH and irradiation time was different, according to each pesticide. Finally, the addition of beta-cyclodextrin upon the photochemically induced fluorescence intensity was investigate. The fluorescence intensity was only improved for monolinuron at a concentration of 4 x 10(-3) M of beta-cyclodextrin.

Solving matrix-effects exploiting the second order advantage in the resolution and determination of eight tetracycline antibiotics in effluent wastewater by modelling liquid chromatography data with multivariate curve resolution-alternating least squares and unfolded-partial least squares followed by residual bilinearization algorithms I. Effect of signal pre-treatment.

The effect of piecewise direct standardization (PDS) and baseline correction approaches was evaluated in the performance of multivariate curve resolution (MCR-ALS) algorithm for the resolution of three-way data sets from liquid chromatography with diode-array detection (LC-DAD). First, eight tetracyclines (tetracycline, oxytetracycline, chlorotetracycline, demeclocycline, methacycline, doxycycline, meclocycline and minocycline) were isolated from 250 mL effluent wastewater samples by solid-phase extraction (SPE) with Oasis MAX 500 mg/6 mL cartridges and then separated on an Aquasil C18 150 mm x 4.6mm (5 microm particle size) column by LC and detected by DAD. Previous experiments, carried out with Milli-Q water samples, showed a considerable loss of the most polar analytes (minocycline, oxitetracycline and tetracycline) due to breakthrough. PDS was applied to overcome this important drawback. Conversion of chromatograms obtained from standards prepared in solvent was performed obtaining a high correlation with those corresponding to the real situation (r2 = 0.98). Although the enrichment and clean-up steps were carefully optimized, the sample matrix caused a large baseline drift, and also additive interferences were present at the retention times of the analytes. These problems were solved with the baseline correction method proposed by Eilers. MCR-ALS was applied to the corrected and uncorrected three-way data sets to obtain spectral and chromatographic profiles of each tetracycline, as well as those corresponding to the co-eluting interferences. The complexity of the calibration model built from uncorrected data sets was higher, as expected, and the quality of the spectral and chromatographic profiles was worse.

Determination of photoirradiated tetracyclines in water by high-performance liquid chromatography with chemiluminescence detection based reaction of rhodamine B with cerium (IV).

A simple, selective and sensitive method has been developed for the simultaneous determination of tetracycline, oxytetracycline, chlorotetracycline, demeclocycline, doxycycline and meclocycline based on reversed-phase high-performance liquid chromatography with chemiluminescence detection. The procedure was based on the chemiluminescent enhancement by photoirradiated tetracyclines of the cerium (IV)-rhodamine B system in sulphuric acid medium. The six tetracyclines were separated on an Aquasil-C18 column with a gradient elution using a mixture of acetonitrile and 0.1 mol L(-1) phosphate buffer as mobile phase, photoderivatized using a photoreactor consisting of a tube reactor coil of PFA and a 8W Xenon lamp. Under the optimized conditions, the method was validated with respect to linearity, precision, limits of detection and quantification and accuracy. The relative standard deviation (RSD) on intra-day precision was below 10% and detection limits ranged between 0.12 and 0.34 microg L(-1). The proposed method has been successfully applied to the determination of tetracyclines in surface water samples. A possible mechanism of the chemiluminescence in the system is discussed.

New method for the photo-chemiluminometric determination of benzoylurea insecticides based on acetonitrile chemiluminescence.

The viability of tandem photochemical reaction-chemiluminescence detection has been studied for the determination of five benzoylurea insecticides, namely, diflubenzuron, triflumuron, hexaflumuron, lufenuron and flufenoxuron. The 'on-line' photochemical reaction of benzoylurea pesticides provides an enhanced chemiluminescence response of the pesticides during their oxidation by potassium hexacyanoferrate(III) and sodium hydroxide, whose signal increases with the percentage of acetonitrile in the reaction medium. The determination was performed using a photoreactor consisting of a PFA (perfluoroalkoxy) tube reactor coil (5 mx1.6-mm O.D. and 0.8-mm I.D.) and an 8-W xenon lamp. As the yield of the photoderivatization process and the chemiluminescent signals depend on the percentage of acetonitrile, the chromatographic column (a Gemini C18, Phenomenex 150 mmx4.6 mm, 5-microm particle size) was chosen with the aim of using high percentages of this organic solvent in the mobile phase. Previous studies showed that the rate of the chemiluminescent reaction was very fast. Therefore, a modification was carried out in the detector in order to mix the analytes and reactants as near as possible to the measure cell. The optimised method was validated with respect to linearity, precision, limits of detection and quantification accuracy. Under the optimised conditions, linear working range extends three orders of magnitude with the relative standard deviation of intra-day precision below 10% and detection limits between 0.012 and 0.18 microg mL-1, according to the compound. The proposed method has been successfully applied to the determination of benzoylureas in cucumber with good results.