No abstract

No abstract

No abstract

The glow discharge ionization source operated in the trace levels is becoming the major area of interest in analytical pulsed (or modulated ) power mode offers unique characchemistry. Therefore, any new analytical technique that is teristics not available from its steady state counterpart. It applied to these problems must be extremely sensitive. Other has been well established that higher instantaneous power applications that require molecular mass and elemental comdensities are obtainable without compromising the sample position characterization include clinical analysis, materials integrity when pulsed plasmas are implemented. This chemistry and pharmaceuticals. It is well known that the operating parameter affords higher sputter yields and oxidation state and the chemical form of hazardous materials lower limits of detection relative to the steady state play a vital role in their actual toxic effects on biological plasmas. Of special interest are the discrete temporal systems and the environment in general.7,11,12 In the near regions associated with the modulated plasma. The presfuture, these criteria will play an increasingly important role ence of these time regimes offers temporal selectivity, in measuring and classifying hazardous sites. Subsequently, it allowing the collection of analytical data in a region where is becoming paramount to identify the molecular forms of the contribution from background and contaminant these elements and their corresponding concentrations in species is minimized. These regions are characterized by environmental samples. strikingly different ionization mechanisms. Acquisition of At present, the acquisition of both elemental and molecular data during each of these temporal regimes provides both molecular and elemental information. In this work the information requires mutually exclusive techniques.13 potential use of the pulsed glow discharge for collecting Although this manner of analysis is possible and indeed works concurrent molecular and elemental information was fairly well, it suffers from a number of disadvantages. The explored. This task was accomplished using time-of-flight most apparent shortcomings of using two independent techmass spectrometry ( TOFMS). TOFMS has a significantly niques involve the time needed to complete an analysis and high throughput and duty cycle, making it ideally suited the amount of sample required. Unfortunately, time and for rapid acquisition of spectra. This characteristic allows sample size are two very important factors when considering data acquisition during each of these temporal regions for a potential new technique. Hence, it is apparent that a technique each discharge pulse power cycle, affording concurrent that could limit analysis time and sample size requirements elemental and molecular detection. p-Xylene was used as could fill a niche that has so far eluded us. a test molecule for these studies.Currently, there are many mass and optical spectrometry based systems that are well suited for each particular type of analysis. T...

No abstract