Mass spectrometry (MS)-based high-throughput screening (HTS) has tremendous potential as an alternative to current screening methods due to its speed, sensitivity, reproducibility and label-free readout. We recently reported that a new generation matrix-assisted laser desorption/ionization triple quadrupole (MALDI-QqQ) mass spectrometer is ideally suited for a variety of enzyme assays and screening protocols. However, all the targets measured to date had peptide substrates that were easily monitored by selected ion monitoring (SIM) without interference from the MALDI matrix. To further extend the application to enzymes with small molecule, non-peptide substrates, we evaluated this method for measuring enzyme activity and inhibition of acetylcholinesterase (AChE). Due to the potential of MALDI matrix interference, multiple reaction monitoring (MRM) was investigated for selective MS/MS transitions and to accurately measure the conversion of acetylcholine into choline. Importantly, ionization, detection and MRM transition efficiency differences between the substrate and product can be overcome by pre-balancing the MRM transitions during method development, thus allowing for a direct readout of the enzyme activity using the ratio of the substrate and product signals. Further validation of the assay showed accurate concentration-dependent inhibition measurements of AChE with several known inhibitors. Finally, a small library of 1008 drug-like compounds was screened at a single dose (10 microM) and the top 10 inhibitors from this primary screen were validated in a secondary screen to determine the rank order of inhibitory potency for each compound. Collectively, these data demonstrate that a MALDI-QqQMS-based readout platform is amenable to measuring small molecule substrates and products and offers significant advantages over current HTS methods in terms of speed, sensitivity, reproducibility and reagent costs.

A simple and specific method using reversed-phase liquid chromatography coupled with electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) was investigated, which allowed the determination of residues of glyphosate and its metabolite, aminomethylphosphonic acid (AMPA), in soybean samples. An aqueous extraction with liquid-liquid partition followed by protein precipitation was performed before the LC/MS/MS determination. The quantitation of glyphosate and AMPA was performed in positive and negative ESI mode, respectively, using the multiple reaction monitoring (MRM) mode with three transitions for each analyte to enhance the specificity of the method and avoid false positives. The methodology reported in this work is capable of detecting residues of glyphosate and AMPA in soybean samples with limits of quantification of 0.30 and 0.34 mg kg(-1), respectively. This alternative method has throughput advantages such as simpler sample preparation and faster chromatographic analysis.

Recebido em 24/8/11; aceito em 29/8/11; publicado na web em 30/9/11 MASS SPECTROMETRY NOMENCLATURE IN PORTUGUESE LANGUAGE. In commemoration of the International Year of Chemistry this article presents the normalization and standardization of key terms used in mass spectrometry in Portuguese Language.Keywords: mass spectrometry; nomenclature; Portuguese language. INTRODUÇÃOO Ano Internacional da Química (AIQ), em 2011, tem sido celebrado através de diferentes ações. Os colegas, durante este ano, já perceberam o resultado dessa iniciativa tomada na 63 a Sessão da Assembleia Geral da ONU, que visa celebrar a contribuição da Química para a humanidade, com o lema Chemistry -our life, our future. Além da esperada reflexão sobre o estado da arte na Química, as sociedades científicas estão atuando na organização de eventos de grande porte com fóruns internacionais, em ações de divulgação como feiras de ciências e mídia, em ações educativas como confecção de materiais didáticos para o ensino médio, entre outras. Nesse contexto, o Presidente da Sociedade Internacional de Espectrometria de Massas, um dos organizadores do compêndio de nomenclatura na área junto à IUPAC, indicou a membros da Sociedade Brasileira de Espectrometria de Massas e da Sociedade Brasileira de Química que organizassem um material didático sobre o tema em língua portuguesa. O material compilado faz uma adaptação para nossa língua dos termos e definições usados de forma corrente em espectrometria de massas. Para isso, sugerimos a leitura das referências que se encontram no final desse texto, 1-11 onde estão as definições em língua inglesa, com os créditos aos autores pioneiros, que compilaram as terminologias originais. Esperamos que esse material educativo auxilie o grande número de pesquisadores, professores e estudantes que atuam na área e que, assim, possamos ter uma comunicação em espectrometria de massas mais eficiente em nosso idioma. TERMOS EM ORDEM ALFABÉTICAAblação por laser -laser ablation Remoção de material de uma amostra sólida ou líquida, através de energia fornecida por um laser de pulso curto para formar espécies em fase gasosa e partículas.Abundância isotópica natural -natural isotopic abundance A abundância isotópica de um elemento da maneira como encontrado na natureza. Afinidade eletrônica (AE) -electron affinity (EA)Energia mínima necessária para a formação de uma espécie neutra a partir de um ânion radical pelo processo M - Agregado iônico -ion clusterUm íon formado pela combinação, por interações não covalentes, de dois ou mais átomos ou moléculas de uma ou mais espécies quí-

Pharmaceutical discharges into the aquatic ecosystem are of environmental concern and sewage treatment plants (STPs) have been pointed out as the major source of these compounds to coastal zones, where oceanic disposal of sewage occurs through submarine outfalls. Diclofenac (DCF) is one of the most frequently detected pharmaceuticals in water, but little is known about the effects on marine organisms. In this study, we employed a tiered approach involving the determination of environmental concentrations of DCF in marine water and the adverse biological effects for fertilization, embryo-larval development and biomarker responses of the mussel Perna perna. Results indicate that effects in fertilization rate and embryo-larval development were found in the order of mg·L. However, low concentrations of DCF (ng·L) significantly decreased the lysosomal membrane stability and COX activity, as well as triggered DNA damage, oxidative stress and changes in antioxidant defenses. Our results point to an environmental hazard at coastal ecosystems and suggest the need for improvements in the treatment of domestic wastewater aiming to reduce DCF concentrations, as well as regulation on current environmental legislation and monitoring of aquatic ecosystems.