“…Isolation of reference standards for pyrethrins and their derivatives in multi-gram quantities is a prerequisite for studying toxicity and soil degradation for these natural pyrethrins. Wong et al [5], has developed a two-step purification process, in which they have separated it into two groups by normal phase liquid chromatography on silica gel. The separation of pyrethrin, cinerin, and jasmolin within each group was achieved by Centrifugal Partition Chromatography (CPC).…”