When withdrawing a fluid sample from an apparatus at reduced pressures for additional chromatographic analyses, a gas tight plunger syringe proves ineffective as it does not create a substantial pressure differential to pull a fluid from a reduced pressure environment. Resulting from motivation to analyze distillate fractions from a reduced pressure advanced distillation curve (ADC) apparatus, a device was developed allowing one to withdraw precise amounts of sample from an apparatus operating at sub-ambient pressures. The new device uses an external vacuum source to evacuate a syringe barrel, extracting fluids from a chamber at pressures as low as 0.5 kPa. To demonstrate the operation of the newly developed device, ~10 υl of distillate fraction from the reduced pressure ADC apparatus were withdrawn and analyzed by gas chromatography mass spectrometry. Distillate extraction and analyses were performed on two fluids, a predefined validation mixture and commercial soy based biodiesel fuel. The new device is not limited to reduced pressure distillations and may be useful for a variety of applications in which further chemical/compositional analyses are desired on a fluid contained in a reduced pressure environment.
Citation: Journal of Chromatography A
Pub Type: Journals
chromatography, sampling, syringe, vacuum