Abstract:A combined purification pretreatment was developed, coupled with the ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) technique on chloramphenicol detection. The matrixes were dissolved and dispersed by ultrapure water, extracted by ethyl acetate, and cleaned using the hexane purification, followed by the ProElut PLS-A SPE system. The residue targets were achieved on Waters Atiantis T3 column with gradient elution of ultra-pure H2O containing 0.1% ammonium hydroxide and acetonitrile as mobile phases, and detected by UPLC-MS/MS with MRM mode via ESI- ionization. An intra-laboratoryvalidation was tested on this method, while an international ring comparison test involved with 10 famous worldwide laboratories was also conducted. The chloramphenicol revealed good linear ranged from 0.5 to 10.0 ng/mL, while the correlation coefficient (R2) was better than 0.9986. The average recoveries on three levels of 5 matrixes (chicken, duck, bovine, ovine, porcine) ranged from 73.34% to 91.23%, with RSD from 0.66% to 2.91%, exhibiting great recovery and repeatability. The compositestatistical modelsby Mandel, Cochran, and Grubbs magnitudes on the data from 10 laboratories verified that all results satisfied the accuracy requirements of inter-laboratory study and the precision requirement of intra-laboratory study. Statistical analysis showed the new method is universal, precise, and simple,thus it had been approved by the ISO/TC34/SC6 committee as the next generation recommended international method for the chloramphenicol determination. And it has been published in international standardization organization system in August 27, 2021, to provide the reference for the global standards committee to formulate relevant detection standards.