Method for determining titer of gentamicin sulfate fermentation liquor

The invention provides a method for measuring the titer of a gentamicin sulfate fermentation broth, which comprises the following steps: 1) taking the gentamicin sulfate fermentation broth, and acidifying the gentamicin sulfate fermentation broth with concentrated sulfuric acid until the pH value is 1.5-2.0; 2) filtering, and neutralizing the filtrate with a sodium hydroxide solution until the pH value is 7.3 +/-0.5; (3) measuring the neutralized solution, putting into a centrifugal tube, adding a reyd's salt solution, and then centrifuging; 4) washing, precipitating and centrifuging; (5) adding an acetone aqueous solution to dissolve the precipitate, centrifuging, taking supernate, and measuring absorbance by adopting an ultraviolet-visible spectrophotometric method; (6) weighing a gentamicin sulfate standard substance, and preparing supernate according to the same treatment method to obtain a standard curve and a linear regression equation of the relationship between the unit titer and the absorbance of the