Multi-component quantitation of loratadine, pseudoephedrine and paracetamol in plasma and pharmaceutical formulations with liquid chromatography-tandem mass spectrometry utilizing a monolithic column

The purpose of this study was to develop a rapid, simple and sensitive quantitation method for pseudoephedrine (PSE), paracetamol (PAR) and loratadine (LOR) in plasma and pharmaceuticals using liquid chromatography-tandem mass spectrometry with a monolithic column. Separation was achieved using a gradient composition of methanol-0.1% formic acid at a flow rate of 1.0 mL min-1. Mass spectral transitions were recorded in SRM mode. System validation was evaluated for precision, specificity and linearity. Limit of detection for pseudoephedrine, paracetamol, and loratadine were determined to be 3.14, 1.86 and 1.44 ng mL-1, respectively, allowing easy determination in plasma with % recovery of 93.12 to 101.56%.

Determination of fipronil in bovine plasma by solid-phase extraction and liquid chromatography with ultraviolet detection

A fast and efficient method has been developed and validated for the determination of fipronil in bovine plasma. Samples were subjected to solid-phase extraction (SPE) followed by reversed phase liquid chromatography (LC) separation, using acetonitrile/water (60:40 v/v) as the mobile phase with a flow rate of 1.0 mL/min and ultraviolet (UV) detection at 210 nm. Ethiprole was used as the internal standard (IS). The method was found to be linear over the range 5-500 ng/mL (r = 0.999). The limit of quantitation (LOQ) was validated at 5 ng/mL. The method was successfully applied to monitor plasma concentrations following subcutaneous administration of fipronil in cattle.

Determination of levodopa in human plasma by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS): application to a bioequivalence study

A sensitive, accurate and simple method using HPLC-MS/MS was developed and validated for levodopa quantitation in human plasma. Analysis was achieved on a pursuit�� C18 analytical column (5 ��m; 150 x 4.6 mm i.d.) using a mobile phase (methanol and water , 90:10, v/v) containing formic acid 0.5% v/v, after extracting the samples using a simple protein plasma precipitation with perchloric acid. The developed method was validated in accordance with ANVISA guidelines and was successfully applied to a bioequivalence study in 60 healthy volunteers demonstrating the feasibility and reliability of the proposed method.

Determina����o simult��nea de topiramato, carbamazepina, fenito��na e fenobarbital em plasma empregando cromatografia a g��s com detector de nitrog��nio e f��sforo

Topiramate and the other frequently co-administered antiepileptic drugs carbamazepine, phenytoin and phenobarbital were determined in 100 ��L plasma samples by gas chromatography with nitrogen phosphorus detection (GC-NPD), after a one-step liquid-liquid extraction with ethyl acetate, followed by flash methylation with trimethylphenylammonium hydroxide. Total chromatographic run time was 12.5 min. Intra-assay and inter-assay precision was 2.5-7.3% and 1.6-5.2%, respectively. Accuracy was 100.1-104.2%. The limit of quantitation was 1 ��g mL-1 for all analytes, proving suitable for routine application in therapeutic drug monitoring of antiepileptic drugs.

Quantification of the uranium concentration in human urine by inductively coupled plasma-sector field mass spectrometry (ICP-SFMS)

In this study, the validation of a method for analyzing the uranium (U) concentration in human urine samples by inductively coupled plasma-sector field mass spectrometry (ICP-SFMS) was conducted. PROCORAD (the Association for the Promotion of Quality Control in Radiotoxicological Analysis) provided two urine samples spiked with unknown contents of U (Sample A = 33.6 �� 1.0 ��g/L and Sample B = 3.3 �� 0.1 ��g/L) and one unspiked sample as a blank. The analyses were directly performed on the diluted urine samples (dilution factor = 1:20) in 5% v/v HNO3. The results obtained by ICP-SFMS corresponded well with the reference values, and the limits of detection were 235U = 0.049 �� 10-3 ��g/L and 238U = 7.37 �� 10-3 ��g/L. The ICP-SFMS technique has been shown to be successful in the analysis of the U concentration in human urine samples and for the quantification of isotopic ratios.

Avalia����o da lixivia����o do c��dmio e n��quel provenientes da degrada����o de baterias n��quel-c��dmio em uma coluna de solo

Spent nickel-cadmium (Ni-Cd) batteries and salts of nickel and cadmium were placed in two different columns of soil for a period of two years. A leaching solution was passed through them at ambient temperature in this period. The behavior of metals in each column was then evaluated. Under the conditions of the experiment, cadmium and nickel demonstrated the potential to contaminate and affect the natural cycles of soil. The disposal of Ni-Cd batteries directly to the soil also increased the concentration of nickel (349 mg kg-1) and cadmium (2890 mg kg-1), sometimes exceeding the intervention values defined in CONAMA resolution 420/09.

Determination of triamterene in human plasma and urine after its cloud point extraction

A new analytical approach was developed involving cloud point extraction (CPE) and spectrofluorimetric determination of triamterene (TM) in biological fluids. A urine or plasma sample was prepared and adjusted to pH 7, then TM was quickly extracted using CPE, using 0.05% (w/v) of Triton X-114 as the extractant. The main factors that affected the extraction efficiency (the pH of the sample, the Triton X-114 concentration, the addition of salt, the extraction time and temperature, and the centrifugation time and speed) were studied and optimized. The method gave calibration curves for TM with good linearities and correlation coefficients (r) higher than 0.99. The method showed good precision and accuracy, with intra- and inter-assay precisions of less than 8.50% at all concentrations. Standard addition recovery tests were carried out, and the recoveries ranged from 94.7% to 114%. The limits of detection and quantification were 3.90 and 11.7 ��g L-1, respectively, for urine and 5.80 and 18.0 ��g L-1, respectively, for plasma. The newly developed, environmentally friendly method was successfully used to extract and determine TM in human urine samples.

CONSTRU����O DE UM REATOR DE PLASMA DESCARGA CORONA PARA ELIMINA����O DE COMPOSTOS ORG��NICOS VOL��TEIS

The impacts derived from the emission of volatile organic compounds (VOC) into the atmosphere can have harmful consequences for human health and the environment. In this regard, the present paper proposes the construction of a low-cost cold plasma reactor for the treatment of these compounds. Tests with the prototype were performed to confirm the efficiency for BTEX (benzene, toluene and xylene) samples. Degradation efficiency was confirmed by the gas chromatography method.

EXTRA����O ASSISTIDA POR ULTRASSOM PARA DETERMINA����O COLORIM��TRICA DE FERRO EM SOLO: UMA COMPARA����O COM ESPECTROMETRIA DE MASSA COM PLASMA INDUTIVAMENTE ACOPLADO

A simple procedure for ultrasound-assisted extraction and colorimetric determination of iron in soil samples was developed. The iron concentration in the analyzed samples was determined by the colorimetric method and the results compared with inductively coupled plasma mass spectrometry (ICP-MS). Fifteen soil samples were analyzed and the iron concentration results compared with those obtained by ICP-MS using microwave-assisted sample digestion. The proposed procedure showed good efficiency for iron extraction and the results obtained by colorimetric determination exhibited good agreement with ICP-MS. Moreover, ultrasound-assisted extraction and colorimetric determination is a simple, fast and low-cost procedure for application in routine analysis.

BIOORGANIC CONCEPTS INVOLVED IN THE DETERMINATION OF GLUCOSE, CHOLESTEROL AND TRIGLYCERIDES IN PLASMA USING THE ENZYMATIC COLORIMETRIC METHOD

Bioorganic and biological chemistry have been found to be highly motivating to undergraduate students and in this context, biochemical blood parameter analysis emerges as highly attractive content. In this proposal, several aspects related to analyses of glucose, cholesterol and triglycerides using the enzymatic colorimetric method were involved, and the findings have at least two relevant implications: i) introducing students to connections between organic chemistry and biology based on enzymatic processes, including reactivity and mechanistic aspects; ii) performing a micro scale bioassay analysis. The proposal requires two theoretical classes (2 h per class) and one practical class (4 h).

Press��o interna e refra����o molar dos sistemas dimetilsulf��xido + tiofeno, dimetilsulf��xido + piridina a 298,15K

Press��o interna, volume livre, refra����o molar e propriedades termodin��micas de excesso de misturas l��quidas bin��rias de dimetil sulf��xido + tiofeno e dimetil sulf��xido + piridina a 298.15K foram calculadas a partir de medidas experimentais de densidades, tens��o superficial e ��ndice de refra����o. A rela����o entre a press��o interna, volume molar de excesso, refra����o molar, e a intera����o molecular dos sistemas bin��rios �� examinada.

Remo����o de ��ons met��licos de solu����es aquosas, por apatitas sint��ticas, usando o m��todo de troca i��nica em coluna

Foi investigada a remo����o dos ��ons Al3+, Mn2+, Cu2+, Zn2+, Cd2+ and Pb2 +, em solu����o aquosa, por apatitas sint��ticas usando o m��todo de coluna. Sob as mesmas condi����es, hidroxiapatitas foram mais seletivas para a remo����o de c��tions que carboapatitas. Usando hidroxiapatita, a capacidades de troca aumentaram na seguinte ordem: Mn2+ < Zn2+ < Cu2+ < Cd2+ < Al3+ < Pb2+. A seq����ncia acima �� similar a obtida em trabalhos pr��vios, usando o m��todo de batelada. An��lises de DRX e IV indicaram a forma����o de uma fase ��nica atribu��da a uma Pb-apatita.

Desenvolvimento e valida����o de m��todo anal��tico para determina����o simult��nea de catecolaminas em ��rg��os reprodutores de ratos por cromatografia l��quida de alta efici��ncia com detec����o eletroqu��mica

O objetivo deste trabalho foi propor um m��todo r��pido e sens��vel para a determina����o simult��nea de catecolaminas (noradrenalina e adrenalina) em amostras de ��rg��os reprodutores de ratos machos por Cromatografia L��quida de Alta Efici��ncia com Detec����o Eletroqu��mica. O m��todo envolveu a inje����o direta do extrato ��cido da amostra de tecido em uma coluna cromatogr��fica com superf��cie interna de fase (HSA-C18), empregando a fase m��vel foi composta por solu����o de ��cido metanosulf��nico a 0.013mol L-1 (pH = 3.0): acetonitrila (96:4v/v), 0,033g ��cido heptanosulf��nico e 0,01g EDTA. A detec����o dos analitos foi obtida, atrav��s de um detector eletroqu��mico L-ECD-6-A-Shimadzu com potencial em 85mV. A extra����o das catecolaminas foi utilizado ��cido percl��rico a 0,4 mol L-1. A extra����o do analito resultou em valores de recupera����o entre 56% e 114%, e coeficiente de varia����o entre 3,8% a 23%. O limite de quantifica����o do m��todo ficou entre 0,008 e 0,030 ng mg-1 para a noradrenalina, e 0,009 e 0,051 ng mg-1 para a adrenalina. Em conclus��o, o m��todo anal��tico foi validado e aplicado com desempenho ��s amostras reais de tecidos biol��gicos de ratos, permitindo a determina����o de baixas concentra����es das catecolaminas estudadas. O m��todo apresentou v��rias vantagens: rapidez, alta precis��o, boa seletividade e, ainda, n��o requer o pr��-tratamento da amostra.

A causalidade em Deleuze: diferen��a interna e produ����o de si

O artigo procura acompanhar as linhas de for��a envolvidas na concep����o deleuzeana de causalidade, particularmente em suas dist��ncias para com as no����es equivalentes no mecanicismo, no platonismo e no hegelianismo. O interesse �� ressaltar como tal no����o, desde que sublinhada como causalidade interna ou causa sui, favorece o estabelecimento da diferen��a como origem do ser, requisito ontol��gico fundamental no pensamento de Deleuze. Para tanto, mostraremos, argumentando em favor da pertin��ncia do coment��rio de Michael Hardt, o contexto que, atravessando especialmente as rela����es de Deleuze com a produ����o de Bergson, situa a causalidade na iman��ncia, na mesma medida em que a afasta do territ��rio da nega����o. Nessa dire����o, vamos nos valer ainda de aspectos vinculados a uma interessante controv��rsia de tradu����o.