PROCESS FOR PRODUCING STANDARD GAS MIXTURE AND APPARATUS FOR PRODUCING THE SAME

摘要

The present invention relates to a process and an apparatus for producing standard gas mixtures for testing or calibrating highly sensitive analytical instruments such as an atmosperic- pressure ionization mass spectrometer (APIMS). According to the invention, the following steps can be carried out: introducing the gas to be analyzed in a controlled way into the analyzing device; adding to the gas to be analyzed, calibrated amounts of gaseous species in order to apply the standard addition and internal standard generation methods; introducing a blanc or zero gas into the analyzing device; adding to the zero gas calibrated amounts of gaseous species in order to generate controlled mixtures facilitating the calibration of the analyzing device; diluting in a controlled way the gas to be analyzed by the zero gas before introduction of the mixture into the analyzing device. This last point is particularly relevant for very polluted, or toxic and/or corrosive gases. The above steps are completed without the addition of contaminants, which is specially important when doing ultratrace level analysis.