Sample Preparation

Take the  sample and detect it directly.

Detect Process

①　Take test strip .

②　Put the reaction film  of the test strip in the sample for 5 min,  take out and discard the excess liquid.

③　Observe the color change of the reaction film within 1-5 min.

Judge the result

Negative:  No color change for Methyl Violet Test Strip and Thymol Blue Test Strip, the sample don’t

contain  Free Mineral Acid In Vinegar.

Positive:    Methyl Violet Test Strip shows blue or grass green color, or Thymol Blue Test Strip shows

Purple color.