More convenient and more reliable: USP recommends new ion chromatography method for zinc oxide assay
9/11/2018

Pharmaceutical cream in squeeze tube

USP has updated the General Chapter <591> «Zinc Determination» monograph to include ion chromatography as the preferred method for measuring zinc oxide. USP 41–NF 36 was developed in partnership with Metrohm and replaces manual titration methods. The new method is approved by the FDA and benefits users with more ease of use and reliability.

Zinc oxide is used in various skin care creams, drugs, and drug products.

USP has replaced the existing manual titration methods with ion chromatography method and has rewritten the General Chapter <591>.

The ion chromatography analysis involves separation of zinc oxide followed by post-column reaction using 4-(2-pyridylazo) resorcinol (PAR) reagent and subsequent detection at 530 nm wavelength.


The new method is documented in the Metrohm Application Note AN-U-076, which can be downloaded from the Metrohm website.

The new method is convenient to use and reliable and is approved by the FDA.

Advantages of using Metrohm IC for zinc oxide assay:
  • Precise software-controlled PCR delivery by patented Dosino technology
  • Simple reagent replenishment for easy use
  • Automatic cleaning of the flow path to prevent reagent crystallization for faster start up and reliability

> Download the Application Note AN-U-076

> Download pr in English