This paper presents a method for analyzing common aerosol propellants and an alternative blending technique for high concentration standards. The analysis was performed using an Agilent Technologies gas chromatograph configured with an automated 6-port gas sample valve, a split injection inlet, an HP-PLOT Q capillary column, and a thermal conductivity detector. Six methods were configured with six different split ratios to create a six-point calibration curve for each standard. Additionally, a method is provided to dynamically dilute samples when a multipoint calibration is desired across a narrow calibration range from a single standard.
This document details a gas chromatography method for analyzing common aerosol propellants, including carbon dioxide, propane, isobutane, n-butane, HFC-152a, HFC-134a, and dimethyl ether. The method utilizes an Agilent 7890A gas chromatograph equipped with a 6-port gas sample valve, split injection inlet, HP-PLOT Q capillary column, and thermal conductivity detector.
The note demonstrates how to configure six different split ratios to create a six-point calibration curve for each standard. It also provides a technique to dynamically dilute samples using the split inlet, allowing for multipoint calibration across a narrow range from a single high-concentration standard.
| Gas sample loop volume | 0.1 mL |
|---|---|
| Inlet temperature | 200 °C |
| Carrier gas | Helium, constant flow mode, 7.0 mL/min |
| Detector | Thermal Conductivity Detector (TCD) |
| Detector temperature | 160 °C |
| Reference flow | 15 mL/min |
A six-point calibration curve is created by configuring six methods with six different split ratios.
Yes, the split inlet can be used to dynamically dilute samples, which is useful for multipoint calibration across a narrow range.