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Drug levels in patients' bloodstreams vary among individuals and consequently therapeutic drug monitoring (TDM) is fundamental to controlling the effective therapeutic range. For TDM purposes, different analytical approaches have been used, mainly based on immunoassay, liquid chromatography- ultraviolet, liquid chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods. More recently a matrix-assisted laser desorption/ionisation method has been proposed for the determination of irinotecan levels in the plasma of subjects under therapy and this method has been cross- validated by comparison with data achieved by LC-MS/MS. However, to reach an effective point-of-care monitoring of plasma drug concentrations, a TDM platform technology for fast, accurate, low-cost assays is required. In this frame, recently the use of paper spray mass spectrometry, which is becoming a popular and widely employed MS method, has been proposed. In this paper we report the results obtained by the development of a paper spray-based method for quantitative analysis in plasma samples of imatinib, a new generation of anticancer drug. Preliminary experiments showed that poor sensitivity, reproducibility and linear response were obtained by the "classical" paper spray set-up. In order to achieve better results, it was thought of interest to operate in presence of a higher and more homogeneous electrical field. For this aim, a stainless steel needle connected with the high voltage power supply was mounted below the paper triangle. Furthermore, in order to obtain valid quantitative data, we analysed the role of the different equilibria participating to the phenomena occurring in paper spray experiments, depending either on instrumental parameters or on the chemical nature of analyte and solvents. A calibration curve was obtained by spiking plasma samples containing different amounts of imatinib (1) with known amounts of deuterated imatinib (1 d3 ) as internal standard, with molar ratios [1]/[1 d3 ] in the range 0.00-2.00. A quite good linearity was obtained (R 2 = 0.975) and some experiments performed on spiked plasma samples with known amounts of 1 confirmed the validity of this method.

Purpose: Using the Problem Oriented Screening Instrument for Teenagers (POSIT), the effect of mode of administration on (1) students' willingness to disclose sensitive information and (2) response rates was investigated., Design: A 2 × 2 unequal N factorial analysis of variance (ANOVA) design was employed. Mode of administration (paper-and-pencil vs. Web-based) was crossed with grade level (middle vs. high school)., Setting: The study was conducted in two middle and two high schools., Subjects: A total of 628 middle and high school students completed the survey., Measures: The POSIT is a self-report measure with 139 yes/no items that identifies stressors in 10 functional areas (e.g., Substance Use)., Analysis: An unequal N 2 (mode) × 2 (grade level) factorial ANOVA was employed., Results: No statistically significant differences were found for self-reported risk across modes of administration. Students completing the Web-based version of the survey were four times more likely to skip an item., Conclusions: Effect of Mode on Reporting of Sensitive Information-Students completed the Web-based surveys in computer labs with other students. The intent of the Web-based survey was to increase perceived privacy but the environment likely negated any effect. Effect of Mode on Response Rates-The higher response rate for the paper-and-pencil survey was the opposite of what was expected and revealed that students were more likely to skip sensitive items on the Web survey., (Copyright © 2011 by American Journal of Health Promotion, Inc.)

The application of low-temperature pyrolysis mass spectrometry to the identification of some commercial and synthetic polymers using a direct insertion probe and electron ionization has been studied. The polymers were analyzed directly in the solid probe of a mass spectrometer within the ion source at 70 eV electron impact. The quadrupole mass spectrometer, equipped with a gas chromatogram software and library of low molecular weight compounds, was used to characterize the polymers by measuring the chemical structure of the repeat units and the end groups, and to examine the thermal degradation pathways. The polymers investigated show different degradation pathways. Investigation of sequences and determination of composition of copolymers were studied. Total ion pyrogram and spectrum subtractions were used to separate and measure spectra of pyrolysis steps at distinctly different temperatures.