Development of an Ultra-Micro Sample Injector for Gas Chromatography Using Ink-Jet Microchip

We have developed an ultra micro sample injector for a gas chromatography (GC). An ink-jet chip, originally used for industrial recorder, was modified at the edge near the orifice and fixed into the GC. To evaluate the characteristics of this injector, a sample injector and a thermal conductive detector (TCD) were connected directly and water was used as the sample. The volume of the droplet, the interval time and the back pressure to the ink-jet chip were investigated. Within a range of 1 ~ 5 nl of sample injection, the TCD response according to the amount of the sample volume (about the volume of 1 drop from the ink-jet micro chip: about 1 nl) was obtained. The reproducibility of the peak area was obtained to be about 1.0% of the RSD value. To compare the injection method of the ink-jet chip with that of the usual micro syringe, a method using the ink-jet chip could introduce 1/1000 amount of the sample and give reproducible result.