Calibration is accomplished using a single n-alkane vapor standard. A library of retention times of known chemicals indexed to the n-alkane response (Kovats indices) allows for machine independent measurement and compound identification. Chemical Analysis (Chromatography) The time derivative of the sen¬sor spectrum (Figure 3) yields the spectrum

detector may experience overloading at the lowest temperature settings. Ethanol Minimum Detection Limit A measurement detection limit is defined by replicate measurements at the lowest quantifiable level. Statistically this is defined for 7 replicate measurements as 3.14 x standard deviation. Using a 1ps2a1b method, 70oC valve, 50oC inlet,

optimize the trapping efficiency of the loop trap system temperatures are necessarily low. Maximum SAW sensitivity is achieved by using a crystal temperature of 10oC or 0oC. A valve temperature of 70oC and an inlet temperature of 50oC are recommended. Because the loop trap contains only 1

using a side-ported sample needle and PTFE filter attached to the inlet of the zNose? as shown in Figure 14. The concentration of ethanol in headspace vapors from water at room temperature is very low because ethanol is very soluble in water. Heating the water sample using a

optimize the trapping efficiency of the loop trap system temperatures are necessarily low. Maximum SAW sensitivity is achieved by using a crystal temperature of 10oC or 0oC. A valve temperature of 70oC and an inlet temperature of 50oC are recommended. Because the loop trap contains only 1

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

and 10oC detector temperatures, 7-replicate measurements at 100 and 13-ppm ethanol concentrations yield MDLs of 14.1 and 5.2 ppm respectively as shown in Figure 13. . Detection of Ethanol in Water Headspace vapors from water standards (20 mL water in a 40 mL vial) were sampled directly