Accuracy in quantification of vitamin A levels in coconut cooking oil using a portable device: agreement, sensitivity and specificity

Abstract Number Theme Presentation Type Cover Approved
0345 Innovations in methods for monitoring and surveillance of programs Poster Not Approved

Authors

Abstract Content

Objectives

To assess the reliability of iCheck Chroma to estimate retinyl palmitate and classify coconut oil as adequately fortified.

Methods

The test device (iCheck Chroma ; Bioanalyt Gmbh) which rapidly quantifies retinyl palmitate was tested against high-performance liquid chromatography (HPLC). Recovery, linearity and precision were measured at five target concentrations (5 to 25 mg Retinol Equivalents (RE)/kg). Agreement (Bland-Altman) was described and the diagnostic performance (sensitivity, specificity and predictive values) was calculated with HPLC as the gold standard.

Results

Linearity ranged from 5 – 27.8 mg RE/kg and recovery was 84 – 130%. Precision ranged from 3.5% to 7.3% (intra-assay) and 1.3 to 14.7% (inter-assay). Mean difference was 1.9 mg RE / kg (SD 2.3; 95% CI 1.44, 2.37). Both methods classified 10 samples as unfortified or inadequately fortified. The specificity was 96% and the positive predictive value was 94% (IRR) and 100% for the IRR20. Sensitivity improved from 62% to 83% (IRR) and 93% to 98% (IRR20) subtracting the mean difference from iCheck reading.

Conclusions

The portable iCheck can be recommended for estimating vitamin A content in fortified coconut cooking oil in lieu of HPLC.

Our website uses cookies to ensure you have the best experience.
Please visit our Privacy Policy page for more information.