Frit spargers

Introduce about 250 mg of sample (W) accurately weighed, on the fritted sparger of the sample purge. Purge and desorb according to equipment instructions. Record the peak area of trichloroethylene, and read the corresponding weight (X) of trichloroethylene from the calibration curve. Calculate the amount of trichloroethylene by the formula... 

Three types of purging vessels are commonly used frit spargers, fritless spargers, and needle spargers. The frit creates fine gas bubbles with large surface areas, which facilitate mass transfer of analytes into... 

Figure 2.21 Possibilities for sample introduction in purge and trap, (a) U tube with/without frits (fritiess/frit sparger) for water sampies. (b) Sampie vessei (needie...

Standards are prepared in organic free water. Each standard gets transferred into a 40 mL sampler vial and loaded onto the P T autosampler. A 5 mL aliquot is transferred automatically from the 40 mL vial into a fritted sparger for analysis. 

The purge efficiency is defined as that quantity of the analytes, which is purged from a sample with a defined quantity of gas. It depends upon various factors. Among them are purge volume, sample temperature and nature of the sparger (needle or frit), the nature of the substances to be analysed and that of the matrix. 

Figure 2.23 Glass apparatus for the purge and trap technique (Tekmar). (a) U-tube with/without frit (5 and 25 mL sizes), (b) Needle sparger left single use vessels, middle glass needle with frits, right vessels with foam retention, 5, 20 and 25 mL volumes.

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