FLOW-INJECTION DETERMINATION OF WATER IN ORGANIC-SOLVENTS BY NEAR-INFRARED SPECTROMETRY

A flow-injection (FI) procedure was developed for the direct determina tion Of Water in organic solvents by using the O-H stretch absorbance band of water in the near-infrared (NIR) region. Dichloromethane was e mployed as a test solvent to study the influence of the flow parameter s (carrier flow and sample injection volume) and time interval on the sensitivity and repeatability of the FI-NIR measurements. The develope d procedure permits the determination of water in dichloromethane and isobutyl methyl ketone samples with limits of detection of 0.01 and 0. 005% (v/v), respectively. Real and spiked samples of solvents were ana lysed by FI-NIR and accurate results were found. The method is rapid, it does not require any pretreatment of samples and it is free from co ntamination of samples by atmospheric humidity .