direct injections of liquid standards do not contain high molecular weight compounds and are less than 1 microliter. Similarly when sampling air in dusty environments a pre-filter should be used to prevent particles from entering the inlet of the instrument. Sampling headspace vapors above liquid samples should be

is shown to be a useful tool for quantifying the concentration of ethanol in air and water samples. How the zNose™ Quantifies the Chemistry of Aromas A simplified diagram of the zNose™ system shown in Figure 2 consists of two sections. One section uses helium

552 and concentration as 415 ppm The zNose® system response is linear over a wide range of vapor concentrations. This is clearly shown by the N-point responses obtained from a series of 1-liter tedlar bags injected with increasing amounts of ethanol as shown in Figure 11. Detector Sensitivity vs

direct injections of liquid standards do not contain high molecular weight compounds and are less than 1 microliter. Similarly when sampling air in dusty environments a pre-filter should be used to prevent particles from entering the inlet of the instrument. Sampling headspace vapors above liquid samples should be

performed with water samples elevated to at least 40oC. Use of a PTFE inlet filter is recommended to prevent water droplets from forming, entering the instrument, and possibly damaging the sensitive vapor detector. A summary chart of ethanol MDL amounts is shown in Table I. For good

lower limit of detectable compounds which can be analyzed by the zNose. Sensitivity is determined by the loop trap’s ability to concentrate ethanol from air samples and the ability of the SAW sensor to condense and detect it as it elutes from the GC column. To

dependent, allow the instrument to display air concentrations as ppmv values. As an example, the ethanol response using a 415 ppmv vapor standard is compared to that of n-alkane vapors (C6-C10) using a 1ps3a1b method in Figure 10. The system software correctly displays the Kovats index of ethanol as