Treatment liquid for exclusion of steroid included in cyclodextrin

A method for immunologically quantifying a steroid, comprising:

• adding to a standard solution containing a target steroid and cyclodextrin, wherein the target steroid is included in the cyclodextrin and wherein the standard solution contains the target steroid at a predetermined concentration, a treatment liquid to exclude the target steroid from the cyclodextrin to form a standard solution treatment liquid mixture;
• reacting an anti-steroid antibody with each of a test sample containing the target steroid and the standard solution treatment liquid mixture to form antigen-antibody complexes in each of the test sample and the standard solution treatment liquid mixture;
• measuring a signal intensity of the antigen-antibody complexes in each of the test sample and the standard solution treatment liquid mixture, wherein the signal intensity of the antigen-antibody complexes measured in each of the test sample and the standard solution treatment liquid mixture is a luminescence intensity of light;
• and
• comparing the signal intensity of the test sample with the signal intensity of the standard solution treatment liquid mixture, to determine a concentration of the target steroid concentration in the test sample,
• wherein the treatment liquid comprises a surfactant as an active ingredient, and wherein the surfactant is at least one selected from the group consisting of N-octanoyl-N-methylglucamine and 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate.