Validation of a Method for Determination of beta-cryptoxanthin in Satsuma Mandarin (Citrus unshiu Marc.) by Interlaboratory Study

摘要

An interlaboratory study was performed to evaluate an analytical method for the determination of,8 cryptoxanthin in satsuma mandarin (Citrus unshiu Marc.). The detection limit (S/N = 3) and determination limit (S/N = 10) of beta-cryptoxanthin in this method were 0.4 mg/kg and 1.2 mg/kg, respectively. Eleven participating laboratories independently analyzed five test materials (five pairs of blind duplicates) using high performance liquid chromatography. After removal of outliers, the repeatability (RSDr) and reproducibility (RSDR) of the evaluated methods were 2.0-4.2 % and 9.0-14 %, respectively, in a concentration range from 4.7 mg/kg to 23 mg/kg. The HorRat values of the beta-cryptoxanthin concentration were calculated to be 0.75 to 1.1. The present study showed that this method has acceptable precision. The expanded uncertainty U(k=2) was 21 %.