What CRMs are specified for photometric accuracy and precision tests by both Pharmacopeias?
USP: for UV range, Nicotinic acid in HCl (6 – 60 mg/L, up to 2.5 A, 213 and 261 nm) or K2Cr2O7 in HClO4 (6 – 200 mg/L, up to 3.0 A, 235, 257, 313, 350 nm); for visible range, neutral density glass filters (up to 3.5 A, 440, 465, 546.1, 590, and 635 nm)
Ph. Eur.: Suitable solid and liquid filters such as certified PDC or neutral density filters; or, instead of certified PDC, Nicotinic acid in HCl.
What CRMs are specified for photometric linearity tests by both Pharmacopeias?
USP and Ph. Eur., respectively, specify to use the materials for photometric accuracy tests also for photometric linearity tests.