Method for detecting aldehydes or ketones

A method for detecting aldehydes or ketones comprising the steps of:

• (S1) providing a rotary micro device comprising one or more structures disposed on a rotary platform, wherein each of the structures includes a sample storage unit filled with a derivatizing compound for aldehydes or ketones, an eluent storage unit, a thin layer chromatography (TLC) plate equipped with an absorption pad, a first micro-channel connecting the sample storage unit and the TLC plate and having one or more bent portions, and a second micro-channel connecting the eluent storage unit and the TLC plate and having a plurality of bent portions, the number of the plurality of bent portions of the second micro-channel being more than the number of the one or more bent portions of the first micro-channel, and supplying a fluid sample containing aldehydes or ketones and an eluent for deploying the sample to the sample storage unit and the eluent storage unit, respectively;
• (S2) performing derivatization of the aldehydes or the ketones by carrying out a first rotation of the rotary micro device to react the fluid sample with the derivatizing compound filled in the sample storage unit;
• (S3) introducing the fluid sample containing the derivatized aldehydes or ketones into the TLC plate by carrying out a second rotation of the rotary micro device;
• (S4) performing TLC separation of the sample by carrying out a third rotation of the rotary micro device to introduce the eluent into the absorption pad of the TLC plate and moving the eluent absorbed into the absorption pad;
• (S5) drying the TLC plate by carrying out a fourth rotation of the rotary micro device;
• and
• (S6) repeatedly performing the TLC separation of the sample by carrying out a fifth rotation of the rotary micro device to introduce the eluent back into the absorption pad of the TLC plate and moving the eluent reabsorbed into the absorption pad, wherein the derivatizing compound is 2,4-dinitrophenylhydrazine (2,4-DNPH), wherein the rotary platform is fabricated by assembling an upper layer portion, a middle layer portion and a lower layer portion, wherein the TLC plate equipped with the absorption pad is arranged on the lower layer portion,
• wherein the first micro-channel and the second micro-channel are arranged on the middle layer portion and the upper layer portion,
• wherein the first micro-channel and the second micro-channel arranged on the middle layer portion are a first part of the first micro-channel and a first part of the second micro-channel respectively, and the first micro-channel and the second micro-channel arranged on the upper layer portion are a second part of the first micro-channel and a second part of the second micro-channel respectively,
• wherein the first part of the first micro-channel includes a bent portion connected to the sample storage unit and the first part of the second micro-channel includes a bent portion connected to the eluent storage unit are arranged on the middle layer portion, and wherein the second part of the first micro-channel includes a portion connected to the TLC plate and the second part of the second micro-channel includes a portion connected to the TLC plate are arranged on the upper layer portion.