Test Standard of CS Liquid Solution is very strict， there are several steps about testing:
Take a little sample first, and then dissolve the sample by acetonitrile with 15cm C18 column; acetonitrile : water = 1:1; gradient elution with eluent,
the tested wave length is 210.
We tested the sample today, with the sample front end shows the system solvent peak. There is hardly and impurities in the sample. During the melting
operation attention must be paid that polar solvent shall be avoided.
Every time before the test, the sample shall be newly made, for the sample shall dissolve slowly in the solution, it is not as stable as solid form.