Determination of two drugs of abuse in saliva has been performed by Paper Spray Ionization Mass Spectrometry (PSI-MS) using a Molecularly Imprinted Polymer (MIP) coated paper as substrate. The method has been optimized for quantification of 3,4-methylenedioxy- N-methylamphetamine (MDMA) and methamphetamine, 3,4-methylenedioxyamphetamine (MDA) from synthetic saliva samples. Rapid analysis (~ 1 min) of designer drugs in saliva is demonstrated using MIP-PSI-MS. Both precursor ions of MDMA and MDA were confirmed by tandem mass spectrometry (MS/MS) experiments by elucidating the fragmentation patterns formed via collisioninduced dissociation (CID). The MIP-PSI-MS method showed greater selectivity for MDMA and MDA in comparison with other analytes. Signal intensity ratios of the most important transitions for MDMA (194 →163) and MDA (180 →163) were found linear (R > 0,99) in the range 25-500 µg L-1. The LOD and LOQ for MDMA were 1.11 µg L-1 and 18.73 µg L-1, respectively, and for MDA were 3.42 µg L-1 and 21.66 µg L-1, respectively. The precision and accuracy values were determined below 4%, and the recoveries about 100%, without pre-concentration/enrichment or separation steps. The MIP-PSI-MS method displays the potential for rapid screening for selective quantitative determination of illicit drugs in saliva samples.

Paper spray ionization (PSI) is a promising analytical tool for direct analysis in mass spectrometry (MS). However, this technique usually uses chromatographic paper, which rarely accomplishes a stable MS signal and could vary with the sample matrix effect. In the present study, the application of graphene oxides (GO) was scrutinized as modifier paper substrate for PSI-MS methods. The developed substrate efficiency was evaluated towards creatinine determination in urine samples. The GO-PSI-MS developed method for creatinine in urine samples showed linearity in the range of 0.1 to 3.4 ppm with R2 = 0.9991. The precision was evaluated and the values were between 1.1 to 6.8% and the accuracy above 96.8%. The limit of quantification (LOQ) and limit of detection (LOD) were 0.05 and 0.17 ppm, respectively. The GO-PSI developed was compared to conventional chromatographic paper for PSI-MS methods, and the results showed that the modified paper with GO bolsters method linearity, precision, and LOQ values.

Jatropha curcas L. is an oil crop that has been studied as a potential source of biodiesel. A high protein pie is produced as a byproduct of the biodiesel production, which could be used as animal feed. However, the pie has toxic compounds, as phorbol esters and other toxins, which prevents the use as animal feed. For this reason, Embrapa (Brazilian Agricultural Research Corporation) has been working in genetic breeding to develop non-toxic J. curcas genotypes. To evaluate this process, a simple and fast analytical technique was employed to obtain responses in a short time. Leaf spray (LS) is a recent ambient ionization mass spectrometry technique in which the sample itself serves as support and ion source. Here, toxic and non-toxic J. curcas leaves were differentiated by LS using a linear ion trap mass spectrometer and partial least squares discriminant analysis (PLS-DA) model chemometrics. It was possible to differentiate toxic and non-toxic leaves and to identify the m/z values that contribute to discrimination between the groups.

A composição química dos óleos essenciais foi utilizada para estudar a estrutura espacial de oito populações de Eugenia dysenterica do Cerrado central brasileiro. O particionamento da variação utilizando os conjuntos de dados espaciais e ambientais como preditores foi altamente significativo e explicou 7,8 e 8,1% da variação total dos óleos essenciais, respectivamente. Os resultados sugeriram que o polimorfismo nos óleos essenciais foi determinado mais por fatores genéticos do que ambientais. Além disso, o intercepto do autocorrelograma multivariado de Mantel entre as matrizes de distância dos constituintes químicos e dos locais de coleta sugere que as populações se diferenciam quimicamente a distâncias geográficas superiores a 120 km, contribuindo como indicador alternativo da distância mínima entre amostras necessária para a conservação da diversidade genética das populações.

The chemical composition of essential oils was used to study the spatial structure of eight Eugenia dysenterica populations in central Brazilian Cerrado. Variation partitioning using spatial and environmental data sets as predictors was highly significant and explained 7.8 and 8.1% of oil chemovariations, respectively. Results suggested that essential oil polymorphism was genetically rather than environmentally determined. Furthermore, the intercept of the multivariate Mantel autocorrelogram between the distance matrices of oil constituents and sampling sites suggested that the populations differ chemically whenever geographical distance exceeds 120 km. It stands, therefore, as an alternative indicator of the minimal distance between samples required for conserving the genetic diversity of populations.