Choline is an amine essential to maintenance of good health. Here, we modified the ion chromatographic method for measuring choline described by Laikhtman & Rohrer and validated by the ICH guideline and applied it to monitoring of choline content in infant formula in the Republic of Korea.
The Certified Reference Materials (CRM), NIST 1849a, were used for validation of the modified method. The parameters of validation were linearity, range, specificity, accuracy, precision, LOD, LOQ and recovery. The linearity, R2, was above 0.999 and the analytical range was 2.5 to 50 μg/mL. The specificity was confirmed by the retention time (RT) and positive tests with calibration standard and CRM. The accuracy, precision and recovery values were 99.6 ± 2.41 %, 2.42 % and 90.8 - 92.8 %. The LOD and LOQ values were 0.03 mg/kg and 0.17 mg/kg, respectively. Five livestock products inspection agencies voluntarily participated in the collaborative study. The result, HORRAT value was 0.8 which was within the reference value 0.5 – 2.0. The validated method was applied to the analysis of choline in infant formula in the Republic of Korea. The results also conformed to 'The Standard for Livestock Products Labeling'.

Abstract
 서 론
 재료 및 방법
  시약 및 시료
  표준용액의 조제
  시료 전처리
  기기분석 조건
  시험법 검증
  유통 시료 모니터링
 결 과
  시험법 검증
  유통 조제분유 모니터링
 고 찰
 REFERENCES

• Ji-Sung Park(Seoul Regional Office, Animal and Plant Quaratine Agency)
• Eun-Chae Ryu(Gyeongin Regional Office, Food and Drug Safety)
• Jae-Woo Park(Laboratory Audit and Policy Division, Ministry of Food and Drug Safety) Corresponding Author
• Hyun-Soo Kim(College of Veterinary Medicine, Chongnam National University) Corresponding Author