3. Results and discussion
3.1. The validation of the analytical method
The recoveries for triadimefon and triadimenol were within
89.3%e114.4% at various concentration levels (Table 1), which
were within the range required for residue analysis. The repeatability
of the recovery results, as indicated by relative standard
deviations (RSDs), confirmed that the method is sufficiently reliable
for the pesticide analysis in this study (OECD, 2007). The
limits of detection (LODs) and limits of quantification (LOQs) for
triadimefon and triadimenol were considered to be the concentration
that produced signal-to-noise (S/N) ratio of 3 and 10,
respectively. It was estimated from the chromatogram corresponding
to the lowest point used in the matrix-matched calibration.
The GC-MS extracted ion chromatograms of triadimefon
and triadimenol in jujube beverage were shown in Fig. 3 respectively.
In our study, the LODs of triadimefon and triadimenol were
estimated to be 0.001e0.004 mg kg1, and the corresponding
LOQs were 0.003e0.01 mg kg1 for jujube and its products samples,
respectively. The regression coefficients obtained were
>0.9982 for triadimefon and triadimenol in the range of
0.02e2 mg L1.