Acid 1mM Research Articles

Determination of pharmaceutical and illicit drugs in oral fluid by ultra-high performance liquid chromatography–tandem mass spectrometry

A simple and extremely fast procedure for the quantitative determination in oral fluid samples of 44 substances, including the most common drugs of abuse and several pharmaceutical drugs, was developed and fully validated. Preliminary sample treatment was limited to protein precipitation. The resulting acetonitrile solution was directly injected into an ultra-high performance liquid chromatograph (UHPLC) equipped with a C18 column (100mm×2.1mm, 1.7μm). The mobile phase eluted with linear gradient (water/formic acid 5mM: acetonitrile/formic acid 5mM; v:v) from 98:2 to 0:100 in 5.0min, followed by isocratic elution at 100% B for 1.0min. The flow rate was 0.6mL/min and the total run time was 9.0min including re-equilibration at the initial conditions. The analytes were revealed by a triple quadrupole mass spectrometer operating in the selected reaction monitoring mode. The method proved to be simple, accurate, rapid and highly sensitive, allowing the simultaneous detection of all compounds. The ease of sample treatment, together with the wide range of detectable substances, all with remarkable analytical sensitivity, make this procedure ideal for the screening of large populations in several forensic and clinical contexts, whenever oral fluid sampling has to be preferred to blood sampling, as for example in short retrospective investigations.

Simultaneous determination in hair of multiclass drugs of abuse (including THC) by ultra-high performance liquid chromatography–tandem mass spectrometry

A simple procedure for the quantitative determination in hair samples of 13 common drugs of abuse or metabolites (morphine, 6-acetylmorphine, codeine, amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine, 3,4-methylenedioxymethamphetamine, 3,4-methylenedioxyethylamphetamine, benzoylecgonine, cocaine, buprenorphine, methadone and Δ9-tetrahydrocannabinol) has been developed and fully validated. The analytes were extracted from the matrix by a simple overnight incubation with methanol at 55°C. An aliquot of the extract was directly injected into an ultra-high performance liquid chromatography system equipped with Waters Acquity UHPLC BEH C18 column (100mm×2.1mm, 1.7μm). The mobile phase eluted with a linear gradient (water/formic acid 5mM:acetonitrile; v:v) from 98:2 to 0:100 in 4.5min, followed by isocratic elution at 100% B for 1.0min. The flow rate was 0.6mL/min and the total run time was 8.0min including re-equilibration at the initial conditions. The compounds were revealed by a triple quadrupole mass spectrometer operating in the selected reaction monitoring mode. The absence of matrix interferents, together with excellent repeatability of both retention times and relative abundances of diagnostic transitions, allowed the correct identification of all analytes tested. The method proved linear in the interval from the limit of quantification to 5.0ng/mg (1.0ng/mg for Δ9-tetrahydrocannabinol) with correlation coefficient values ranging from 0.9970 to 0.9997. Quantitation limits were below the cut-off values recommended by the Society of Hair Testing and ranged from 0.02 to 0.08ng/mg. Application of the present UHPLC–MS/MS procedure and instrumentation to hair analysis allows high sample-throughput, together with excellent sensitivity and selectivity, in workplace drug-screening controls and forensic investigations. These qualities, combined with minimal sample workup, make the cost of this screening affordable for most private and public administrations.

Bioremediation in marine sediments with Bacillus strain selected in samples from forest soil

Bacillus are a Gram positive bacteria developing high capability of degrading aromatic compounds. By using selective culture media with benzoic acid 5mM as carbon source, thirteen strains of Bacillus were selected in samples from Floresta da Tijuca soil (22' 50' S and 43' 15' W). Samples of marine sediments from Angra dos Reis (23' 30' S and 44' 25' W) were collected and examined for oil mixtures (0.33; 1.54 and 1.78%). The rate of oil mineralization in the marine sediments by the autochthonous microbial communities were 3; 1.65 and 0.8% of CO 2 per hour to 0.33; 1.54 and 1. 78% of oil, respectively. When the samples were inoculated with Bacillus strain, the degree of oil mineralization increased 4.65; 3.4 and 2% of CO 2 per hour to 0.33; 1.54 and 1.78% of oil, respectively. These results show that the presence of Bacillus strain increased the CO 2 production 2.5 folds in sediments with 1.78% of oil, 2 folds in sediments with 1.54% of oil and 1.5 folds in sediments with 0.33% of oil content. The autochthonous microbial communities have a slow response to oil. However, the inoculation of a adapted Bacillus strain is sufficient to induce an increase in the oil degradation