We are glad to offer a high recommendation regarding to Chrom-Matrix SPE and HPLC products. Our CRO partner was requested to determine the concentration of  florfenicol in fish hatchery effluent water. According to EPA’s analytical guidance, solution calibration standards had to be used. After a long time of method trial, they selected Chrom-Matrix SPE cartridges to enrich florfenicol and get rid of so-called matrix effect in LC-MS/MS assay. With the validated method for determination of trace amount of florfenicol (less than 10 ng per liter), florfenicol depletion profile in the fish hatchery sites had been established.