Jornal de Técnicas Analíticas e Bioanalíticas

Abstrato

Development of an On-line GC System using Existing Retired Equipment

Yuhui (Henry) Zhao

To ensure drinking water quality, continual monitoring of the volatile organic compounds (VOCs) in the source water and the treated water is very important for any water treatment plant. On-line, real-time information is crucial to water treatment engineers and operators. The concentration of VOCs provides such information. For VOCs analysis, gas chromatography (GC) is one of the best techniques due to its high sensitivity and selectivity. As a result, an inhouse on-line GC System was developed for this purpose at a water treatment plant. It included the following parts: a stream selection device to connect two sample streams; a self-cleaning filter to remove sands and suspended solids; a Purge-and-Trap (P&T) device to extract and concentrate the volatile compounds; a GC (from Hewlett-PackardTM) equipped with a Flame Ionization Detector (FID) to identify and quantify the compounds; a computer with WindowsTM XP plus ChemStation to control the sampling valves through a DAQ (from National InstrumentsTM) and to control the GC and P&T through a GPIB-USB interface (from AgilentTM). To minimize cost in the development of this system, shelved GC and P&T were used. These instruments have been retired from regular use but still in good working condition.