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USGS · 70022012

Determination of submicrogram-per-liter concentrations of caffeine in surface water and groundwater samples by solid-phase extraction and liquid chromatography

M.R. Burkhardt·P.P. Soliven·S.L. Werner·D.G. Vaught
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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 μg/L. Mean recoveries and relative standard deviations were 93 ± 13% for organic- free water samples fortified at 0.04 μg/L and 84 ± 4% for laboratory reagent spikes fortified at 0.5 μg/L. Environmental concentrations of caffeine ranged from 0.003 to 1.44 μg/L in surface water samples and from 0.01 to 0.08 μg/L in groundwater samples.

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M.R. Burkhardt, P.P. Soliven, S.L. Werner, D.G. Vaught. 2020-01-14. Determination of submicrogram-per-liter concentrations of caffeine in surface water and groundwater samples by solid-phase extraction and liquid chromatography. https://doi.org/10.1093/jaoac%2F82.1.161

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