Analysis of Low Concentration Oxygenates in Environmental Water Samples Using Purge Trap Concentration Gas Chromatograph

About this manual

The document addresses the challenge of detecting polar analytes such as methanol and ethanol at low parts-per-billion levels in ground and drinking water. It highlights that traditional purge and trap methods often require optimization to achieve sufficient sensitivity for these specific additives.

The study details an experimental setup using a 6890 Plus gas chromatograph with a 5973 mass spectrometer and a model 3100 purge and trap system. Key optimizations investigated include increasing sample volume from 5 mL to 25 mL, raising sample temperature to 85°C, and modifying the matrix by adding sodium sulfate to improve recovery rates.

What's inside

• Abstract
• Experimental
• Purge Gas Flow
• Sample Volume
• Sample Temperature
• Matrix Modification

Frequently asked questions

What sample volume was used to achieve better sensitivity?

A 25 mL sample size was used, which resulted in better sensitivity and improved calibration reproducibility compared to the typical 5 mL.

What temperature was considered optimum for sample purging?

A sample temperature of 85°C was considered optimum because it produced a dramatic increase in response compared to lower temperatures.

Which salt was chosen for matrix modification and why?

Sodium sulfate was chosen because it provides superior performance over sodium chloride and does not have corrosive characteristics.