Validated method for trace impurities analysis in bulk gas using Gas Chromatography with Pulse Discharge Helium Ionization Detection

Abstract

Pulse discharge helium ionization detector (PDHID) is developed to respond the need of many applications in the area of chromatographic quantitative analysis. The PDHID is a general type of detector with very high detectability property covering a wide range of chemical compounds. Based on ISO/IEC 17025, a reliable and accurate of measurement result can be obtained by applying a validated method. This paper reports a validation study with regard to the application of GC-PDHID for trace impurity analysis in bulk gases. An optimized operating condition of GC was used to evaluate the method performance with parameters including precision (repeatability and reproducibility), linearity, limit of detection (LoD), and limit of quantification (LoQ). In this study, six trace compounds (CO2, H2, Ar, O2, CH4, and CO) in bulk gas were analyzed. The results show that the validated of the GC-PDHID method was repeatable and reproducible for the analysis of trace impurities in bulk gas. The %RSD of repeatability and reproducibility were found to be < 3.00% and < 10.50%, respectively. Good linearity of the validated method was obtained with the correlation coefficient (R2) higher than 0.99 for all six trace compounds. In addition, the calculated LOD and LOQ of the GC-PDHID were found to be < 0.60 and < 2.00 μmol mol-1 respectively. In conclusion, validated method of the GC-PDHID for the measurement of the six trace compounds in bulk gas is reliable and fit for its purpose, implying that the validated method can be used in daily measurement in the testing laboratory.