Fast determination of bisphenol A in spiked juice and drinking water samples by pipette tip solid phase extraction using cobalt metal organic framework as sorbent

A cobalt metal organic framework was prepared with rapid ultrasound assisted method by treatment of cobalt nitrate with pyridine 2,6-dicarboxilic acid dissolved in ethanolic media and used as a sorbent for pipette tip solid phase extraction of Bisphenol A (BPA) and its determination in spiked juice and drinking water samples by HPLC. Parameters which influence extraction efficiency such as pH, sample volume, amount of sorbent, type and volume of eluent, and number of draw/eject cycles for extraction and elusion were tested and optimized. Results showed that best extraction efficiency could be obtained at pH 3, 150 ？μL of sample volume, 3 mg of adsorbent and 10 ？μL of methanol as elution solvent. Numbers of draw/eject cycles for both sample extraction and elution were 7 cycles. Limit of detection and limit of quantification of this method were 0.07 and 0.3 μg L-1, respectively, with linear dynamic range of 0.3 to 300 μg L-1 for BPA. This method was applied successfully for determination of BPA in five spiked juices and drinking water samples.