*2.5. Specificity of the ICA*

The cross-reactivity tests (CR; %) of the ICA for the analogs of ZEN and the common mycotoxins were carried out in order to assess the specificity of the developed ICA method. It could be observed that ZEN made the red color completely disappear, and α-Zearalenol or β-Zearalenol left the red color markedly diminished, while other compounds caused the T lines to be obviously weaker than that the C line when the compounds were 5 ng/mL in the sample solutions (Figure 5). Further study showed that the CRs of the ICA method for α-Zearalenol, β-Zearalenol, α-Zearalanol, β-Zearalanol, and Zeranol were 13.0%, 10.5%, 0.5%, 0.48%, and 0.35%, respectively, which indicated that the ICA method had a slight specificity for the ZEN analogs. At the same time, the CRs of the ICA method for common mycotoxins were less than 0.1%, which indicated that the ICA method could not identify other mycotoxins. Thus, the developed ICA method had a high specificity for ZEN detection. *Toxins* **2020**, *x*, x FOR PEER REVIEW 5 of 12 color markedly diminished, while other compounds caused the T lines to be obviously weaker than that the C line when the compounds were 5 ng/mL in the sample solutions (Figure 5). Further study showed that the CRs of the ICA method for α‐Zearalenol, β‐Zearalenol, α‐Zearalanol, β‐Zearalanol, and Zeranol were 13.0%, 10.5%, 0.5%, 0.48%, and 0.35%, respectively, which indicated that the ICA method had a slight specificity for the ZEN analogs. At the same time, the CRs of the ICA method for common mycotoxins were less than 0.1%, which indicated that the ICA method could not identify other mycotoxins. Thus, the developed ICA method had a high specificity for ZEN detection.

**Figure 5.** The cross‐reactivity tests of the ICA for ZEN detection. The analogs were 5 ng/mL. (1) negative; (2) ZEN; (3) α‐Zearalenol; (4) β‐Zearalenol; (5) α‐Zearalanol; (6) β‐Zearalanol; (7) Zeranol; (8) Aflatoxin B1; (9) Deoxynivalenol; (10) Fumonisin B1; (11) Ochratoxin A. **Figure 5.** The cross-reactivity tests of the ICA for ZEN detection. The analogs were 5 ng/mL. (1) negative; (2) ZEN; (3)α-Zearalenol; (4)β-Zearalenol; (5)α-Zearalanol; (6)β-Zearalanol; (7) Zeranol; (8) Aflatoxin B<sup>1</sup> ; (9) Deoxynivalenol; (10) Fumonisin B1; (11) Ochratoxin A.
