Title: Analysis of ppb Levels of VOC's and Hydrides by Gas Chromatography (GC) / Photoionization (PID)
Subject Category: Physical Sciences
Session Selection:AAAS General Poster Session
Slot: Sunday, February 17, 2013: 1:00 PM-5:00 PM #9780
Presenting author: Jennifer L. Maclachlan, PID Analyzers, LLC, Sandwich, MA and Jack N. Driscoll, PID Analyzers, LLC Sandwich, MA
The first commercial PID was introduced at the Pittsburgh Conference in 1976 by HNU Systems. This detector was found to be 50-100 times more sensitive than the flame ionization detector (FID). The PID has gone through several redesigns since then and has found a niche in environmental EPA 502, 602, 8040 etc. and trace (ppb) analysis with more than 15,000 units sold.
The fourth generation PID that has been developed has improved noise characteristics in the lamp circuit and in the electrometer. The high voltage circuit employs a Cockcroft Walton multiplier and uses a constant current source instead of a constant voltage design that was used in previous PID’s. This has resulted in a 20-30% reduction in the background noise level and allowed us to achieve sub pg detection levels for aromatic compounds and hydrides. This poster will illustrate the chromatographic improvements achieved with this fourth generation PID.