Abstract:

Based on Evaluation of Uncertainty in Chemical Analysis Measurement, the uncertainties in the determination
of basic orange in chili powder by HPLC were evaluated. According to the developed mathematic model, the sources of
uncertainty were analyzed. The uncertainty components affecting the results were evaluated. The uncertainties from the
preparation of standard solution, the calibration of the standard curve fitted by least square regression, the measurement of
the sample weight, the adjustment of the sample volume, sample treatment, and the repeatability of the results were 0.008 3,
0.056, 0.002 5, 0.005 0, 0.012, and 0.022, respectively. The content of basic orange in spiked chili powder was (30 ± 3.73) mg/kg as
obtained by multiplying the combined uncertainty from the uncertainty components by the expansion factor 2 at 95%
possibility. It was also found that the uncertainty from the standard curve fitted by least square regression had the
largest effect on the results, and the uncertainties from sample treatment and the repeatability of the results could not
be overlooked.

Key words: high performance liquid chromatography, chili powder, basic orange, uncertainty evaluation