Colorimetric Measurement of Fludioxonil

Abstract

A process for determining the fludioxonil content in a liquid medium by performing a color reaction with [4-(dimethylamino)phenyl]methanol (p-DAB) or 4-Dimethylaminocinnamaldehyde (DMACA) and an acid in the presence of fludioxonil and obtaining a colorimetric reading for the resulting mixture after a period of time

Claims

1. A method of performing a color reaction in the presence of fludioxonil in a liquid medium, the method comprising: combining an indicator selected from [4-(dimethylamino)phenyl]methanol and 4-Dimethylaminocinnamaldehyde, with an acid and fludioxonil.

2. The method of claim 1, wherein the indicator is [4-(dimethylamino)phenyl]methanol.

3. The method of claim 1, wherein the acid is phosphoric acid, sulfuric acid, nitric acid, hydrochloric acid, acetic acid, carbonic acid, hydrofluoric acid, citric acid, oxalic acid or boric acid.

4. The method of claim 2, wherein the acid is phosphoric acid, sulfuric acid, nitric acid, hydrochloric acid, acetic acid, carbonic acid, hydrofluoric acid, citric acid, oxalic acid or boric acid.

5. The method of claim 1, wherein the fludioxonil is present in an aqueous medium.

6. The method of claim 1, further comprising heating the resulting mixture at 95° C. for a period of time.

7. The method of claim 6, where the period of time is one hour.

8. The method of claim 1, further comprising obtaining a colorimetric reading after a period of time for the resulting mixture.

9. The method of claim 4, further comprising obtaining a colorimetric reading after a period of time for the resulting mixture.

10. The method of claim 7, further comprising comparing the colorimetric reading to a reference sample.

11. A kit comprising: a. [4-(dimethylamino)phenyl]methanol or 4-Dimethylaminocinnamaldehyde b. an acid; and c. fludioxonil.

12. The kit of claim 6, further comprising: a. one or more container(s); and b. a pipette.

Description

EXAMPLE 1

[0011] Seven reference samples containing known concentrations of fludioxonil were prepared in laboratory tubes by mixing SCHOLAR® SC in the volumes shown in Table 1 with 50 ml of water. Scholar® SC is a well-known and commercially available fungicide sold by Syngenta Crop Protection and contains 20.4 w/w % fludioxonil (1.92 lb fludioxonil per gallon).

TABLE-US-00001 TABLE 1 Reference Scholar ® Water Reference Sample # SC (μL) (mL) Sample Conc. 1 25 50 100 ppm 2 37.5 50 150 ppm 3 50 50 200 ppm 4 62.5 50 250 ppm 5 75 50 300 ppm 6 87.5 50 350 ppm 7 125 50 500 ppm

[0012] An indicator solution comprising 2.5 g of p-DAB, 100 ml 85% phosphoric acid, and 5 mL of water was combined in a container thoroughly combined into solution.

[0013] 1 mL of each refence sample are added to individual laboratory tubes (e.g. centrifuge tube or standard test tube) and combined with 1 mL of the indicator solution. The tubes are shaken to mix the solutions and placed in heating block at 95° C. for 1 hour. The result is a color concentration refence spectrum.

[0014] In practice a “sample solution” would also be created concurrently with the reference spectrum. The sample solution is the solution that a person is determining the fludioxonil concertation in, e.g., a water bath containing fludioxonil. The test proceeds in the same manner as the reference samples −1 mL of the sample solution is added to a test tube with 1 mL of indicator solution, the tube is shaken to mix the solution and placed in heating block at 95° C. for 1 hour.

[0015] The color of the sample solution is then compared by eye-sight, or by a colorimeter, to a reference sample to determine the fludioxonil concentration of the sample solution.

[0016] The present technology also includes a kit for performing the colorimetric analysis as described herein. The kit may include standard solutions of fludioxonil. The kit may also include a series of standard solutions, disposable pipets, test tubes (including small tube such as Eppendorf tubes or Corning tubes), gloves, goggles, tube rack, indicator (such as p-DAB or DAMCA), acid solvent; and written instructions.