Table 2. The Number of Aligned Chromatographic Peaks Detected in All 18 Spiked-in Samples Using the XICs Constructed by m/z Variation Window Approach and DBSCAN Approach.

frequencya (%)	number of samples	Δm/z ≤ 7 ppm	DBSCAN
100	18	295	298
80–99	15, 16, 17	255	270
60–79	11, 12, 13, 14	206	223

^aFrequency refers to the ratio of the number of samples from which a chromatographic peak was aligned divided by the total number of samples.