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A simple infrared spectrophotometric method is described for determination of the percentage methoprene (isopropyl (E,E)-11-methoxy-3,7,11-trimethyl-2,4-dodecadienoate, Altosid, ZR-515) in a microcapsule sample of lactic acid polymer material. In the analysis, a weighed microcapsule sample was extracted with toluene–isopropanol in an Erlenmeyer flask, and the solvent mixture was evaporated in a rotary vacuum evaporator. For cleanup, the extract was dissolved in methanol and chromatographed through a column composed of sodium sulfate, silica gel, and aluminum oxide. The solvent was again completely evaporated, the dried eluate was dissolved in an appropriate volume of carbon tetrachloride, and the infrared absorption was scanned. The response can then be related by a standard curve to mg methoprene/mL.

A simple but specific infrared (IR) spectrophotometry method for the quantitative determination of famphur, O,O-dimethyl O-[p-(dimet hylsulf amoyl) phenyl] phosphorothioate, in a capsule sample of lactic acid-polymer material is presented. The analytical method includes the following operations: extracting the encapsulated famphur with CQ4 and heat, cooling the extract to room temperature and diluting to volume with CCl4, and, after filtering through anhydrous H2S04 , determining IR absorption of the sample, which is related by a standard curve to mg famphur/ml solution.