Determination of submicrogram-per-liter concentrations of caffeine in surface water and groundwater samples by solid-phase extraction and liquid chromatography |
| |
Authors: | Burkhardt M R Soliven P P Werner S L Vaught D G |
| |
Affiliation: | U.S. Geological Survey, National Water Quality Laboratory, Denver Federal Center, CO 80225-0046, USA. |
| |
Abstract: | A method for determining submicrogram-per-liter concentrations of caffeine in surface water and groundwater samples has been developed. Caffeine is extracted from a 1 L water sample with a 0.5 g graphitized carbon-based solid-phase cartridge, eluted with methylene chloride-methanol (80 + 20, v/v), and analyzed by liquid chromatography with photodiode-array detection. The single-operator method detection limit for organic-free water samples was 0.02 microgram/L. Mean recoveries and relative standard deviations were 93 +/- 13% for organic-free water samples fortified at 0.04 microgram/L and 84 +/- 4% for laboratory reagent spikes fortified at 0.5 microgram/L. Environmental concentrations of caffeine ranged from 0.003 to 1.44 micrograms/L in surface water samples and from 0.01 to 0.08 microgram/L in groundwater samples. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|