In the process of chemical test fume hood operation, instrument scrubbing is one of the important links in the test operation. Instrument scrubbing generally refers to the glass instrument scrubbing, of course, also refers to the evaporation of dishes, crucibles, mortar other scrubbing. In the chemical test before, has been used in the instrument is necessary to scrub clean, dry standby save.

Clean glass instrument is a good test conditions, especially on the ion identification some quantitative test is more important, otherwise it will directly affect the effect of the test. Commonly used test instrument scrubbing methods are as follows.　

1、Flushing method

Write a small amount of water into the container (generally more than 1/3 of the container volume), oscillation, pouring, repeat several times, then the container mouth down, flushing the outer wall of the container will be placed in the designated direction of the sun. If the test tube, it should be inverted in the test tube rack.

2、Scrubbing method

If the inner wall of the instrument is easy to wash off the material, you can pour a small amount of water into the container, then the appropriate brush to collaborate with the decontamination powder, scrubbing agent, rolling back forth, then quietly flushing after a few times with water can be flushed.

3、pharmaceutical scrubbing method

On the dirt that can be washed away with water, according to the nature of the dirt is the same as the fume cupboard disposal with pharmaceuticals.

① glassware with water-insoluble alkali, carbonates, alkaline oxides MnO2 other substances, can be cleaned with dilute hydrochloric acid (if necessary, can be heated).

② instruments with grease attached, can be cleaned with hot soda solution ( with NaOH solution), phenol can be scrubbed with NaOH solution.

③ adhering to the instrument with sulfur, can be dissolved with CS2 to remove (also available in hot NaOH solution to scrub).

④ The instrument adhering to iodine can be removed by dissolving it with alcohol.

⑤ Test tubes used in the silver mirror test can be washed with dilute nitric acid ( heated if necessary).

(6) Burettes for titration tests should be washed with a specially made “washing solution”. After washing the inside, rinse off the liquid wash it with distilled water 2-3 times.