Application of selected ion flow tube mass spectrometry to real-time atmospheric monitoring.

Data are presented for real-time atmospheric monitoring of volatile organic chemicals (VOCs) in air using selected ion flow tube mass spectrometry (SIFT-MS) technology. These measurements were made by one of the new generation of SIFT-MS instruments. Results are shown for five VOCs that were continually monitored from a stationary sampling point over a 4-day period: ethene, ethanol, 1,3-butadiene, benzene and toluene.

Demonstration of selected ion flow tube MS detection in the parts per trillion range.

The rate coefficients of the ion-molecule reactions between H3O+, NO+, O2+, and phosphine were determined using a selected ion flow tube. Using these data, the selected ion flow tube mass spectrometry (SIFT-MS) method was applied to the real-time measurement of phosphine in nitrogen without sample preparation down to concentrations in the mid parts per trillion range. This is the first reported measurement using SIFT-MS in the parts per trillion range.

Application of selected-ion flow tube mass spectrometry to the real-time detection of triacetone triperoxide.

A fast, efficient, real-time method for the quantitative analysis of the peroxide explosive, TATP, is described. The method utilizes rapid ion-molecule reactions of chemical reagent ions with the vapor above solid TATP. The reactions of three reagent ions (H3O+, O2+, NO+) were examined.

Optical spectra of synechocystis and spinach photosystem II preparations at 1.7 K: identification of the D1-pheophytin energies and stark shifts.

We report and compare highly resolved, simultaneously recorded absorption and CD spectra of active Photosystem II (PSII) samples in the range 440-750 nm. From an appropriately scaled comparison of spinach membrane fragment (BBY) and PSII core spectra, we show that key features of the core spectrum are quantitatively represented in the BBY data. PSII from the cyanobacterium Synechocystis 6803 display spectral features in the Qy region of comparable width (50-70 cm(-1) fwhm) to those seen in plant PSII but the energies of the resolved features are distinctly different.