Brown & Williamson Tobacco Corp.

Infrared spectroscopy is commonly applied to the analysis of small gas-phase molecules. One of the limitations of using Fourier transform infrared (FT-IR) spectroscopy for these applications is the time response of long path length gas cells. Hollow waveguides (HW) that transmit in the mid-infrared spectral range have higher optical efficiencies compared to long path length cells due to smaller cell volumes. This study characterizes a silver coated, 2 mm inner diameter HW for the analysis of carbon monoxide (CO) and nitric oxide (NO) and compares the performance to a 3 m gas cell and traditional gas analyzers. The HW was found to have a CO response time less than the NDIR analyzer and approximately one-tenth of the response time on the FT-IR system equipped with a 3 m gas cell. The utility of the increased response time was demonstrated by measuring CO concentrations in sidestream cigarette smoke at the same temporal resolution as an NDIR analyzer. A 10 to 60% increase in sensitivity using various frequencies for both CO and NO was observed using the HW compared to the 3 m multipass gas cell. However, cost savings for gas-sensing applications can be achieved on a per analyte basis by using FT-IR spectroscopy, especially in combination with a HW gas-sensing module, which is significantly less expensive than a multipass gas cell.

Sample preparation as practiced today in analytical laboratories is a complex combination of classical and modern techniques. In this review, the progress made in the last few years in sample preparation for chromatography is examined and discussed in comparison with previous achievements in the field. Discovery and development of new materials is seen as one of the main sources of progress, but finding better ways of using the old principles and the improvements in technology are also major contributing factors for advancement. Practical demands for analysis of pharmaceutical products, the environmental studies, and life science are the main driving forces for development in sample preparation for chromatography.

ASTM E2058 (NFPA 287) Fire Propagation apparatus was used to determine the Critical Heat Flux (CHF) and Thermal Response Parameter (TRPthin) of 10 fabrics by measuring time to ignition at different heat flux values. CHF values were in the range 15–25 kW/m2 and decreased with fabric areal density and cation content. TRPthin values expressed as areal density heat capacity ignition temperature above ambient were in the range 500–2439kW-s/m2. There was a reasonable correlation between the measured TRPthin values and the areal density of the fabrics examined in this study. Light areal density fabrics with low TRPthin values (≤ 1000 kW-s/m2) had high ignitions with the fast smoldering cigarette, while heavy areal density fabrics (≥ 1200 kW-s/m2) had high ignitions with the slow smoldering cigarette.