Time-/Space-Saving Series of Operations for Quantifying Ractopamine in Beef under Organic Solvent-Free Conditions

To prevent the distribution of drug residual foods, the effective residue analytical method is indispensable. This chapter described an organic solvent-free, simple, and time-/space-saving method of sample preparation followed by high-performance liquid chromatography (HPLC) coupled photo-diode array (PDA) detector for quantifying ractopamine (RP) in beef. The HPLC-PDA procedure was used on an Inertsil®HILIC, hydrophilic interaction chromatographic mode, column with an isocratic aqueous mobile phase. A portable ultrasonic homogenizer was used to extract an analyte from the sample, which was then purified using MonoSpin®SCX centrifugal monolithic silica spin mini-columns and measured in 25 minutes. For sequential analyses, a batch of 24 samples could be analyzed in approximately 7 h. The suggested approach achieved average recoveries for the anlyte in the range of 95.2 – 103.1% with relative standard deviations 2.8%. The quantitation limit was 10 ng g-1 in the flank and liver. In the HPLC-PDA system, RP was easily identified in beef flank and liver samples by its retention time and absorption spectrum without the use of MS or MS/MS (extremely expensive, stable / simple analysis requires skill).