Table 4

Results of validation of HPTLC method [19].

Validation data

Value

linearity

r > 0.99

precision

repeatability of the sample application and intra-day precision

RSD < 3.8%

repeatability of peak-area measurement

RSD < 2.4%

accuracy

RSD < 6.5%

limit of detection

PME 7.5 ng/band

IFA 7.5 ng/band

CA 60 ng/band

limit of quantification

PME 22.5 ng/band

IFA 22.5 ng/band

CA 180 ng/band

robustness

inter-day precision and stability of standard solutions

RSD < 5% (two days)

stability on the plate

RSD < 3.4% (up to 2 hours)*

effect of temperature

RSD < 4.6% (20/26°C)

selectivity

absorption spectra matching > 0.99

*only caffeic acid degraded up to 9.4% in 120 minutes, but as the analysis lasts less, this was not of great significance; CA: caffeic acid; IFA: isoferulic acid; PME: pinocembrin-7-methylether; RSD: relative standard deviation.

Medić-Šarić et al. Nutrition Journal 2009 8:33   doi:10.1186/1475-2891-8-33