A paper test card has been engineered to perform an iodometric titration, an application that requires storage and mixing on demand of several mutually incompatible reagents. The titration is activated when a user applies a test solution to the test card: the dried reagents are reconstituted and combined through a surface-tension-enabled mixing (STEM) mechanism. The device quantifies 0.8-15 ppm of iodine atoms from iodate in aqueous solutions. This is useful, for example, to quantify iodine levels in fortified salt. A blinded internal laboratory validation established the accuracy as 1.4 ppm I and the precision as 0.9 ppm I when the test card was read by newly trained users. Using computer software to process images, the accuracy and precision both improved to 0.9 ppm I. The paper card can also detect substandard β lactam antibiotics using an iodometric back-titration. When used to quantify amoxicillin, good distinction is achieved between solutions that differ by 0.15 mg/mL over a working range of 0-0.9 mg/mL. The test card was designed to meet the World Health Organization ASSURED criteria for use in low resource settings, where laboratory-based analytical procedures are often not available.

The effects of radiation on a variety of uranyl peroxide compounds were examined using γ-rays and 5 MeV He ions, the latter to simulate α-particles. The studied materials were studtite, [(UO 2 )(O 2 )-(H 2 O) 2 ](H 2 O) 2 , the salt of the U 60 uranyl peroxide cage cluster, Li 44 K 16 [(UO 2 )(O 2 )(OH)] 60 •255H 2 O, the salt of U 60 Ox 30 uranyl peroxide oxalate cage cluster, Li 12 K 48 [{(UO 2 )(O 2 )} 60 (C 2 O 4 ) 30 ]•nH 2 O, and the salt of the U 24 Pp 12 (Pp = pyrophosphate) uranyl peroxide pyrophosphate cage cluster, Li 24 Na 24 [(UO 2 ) 24 (O 2 ) 24 (P 2 O 7 ) 12 ]•120H 2 O.Irradiated powders were characterized using powder X-ray diffraction, Raman spectroscopy, infrared spectroscopy, X-ray photoelectron spectroscopy, and UV−vis spectroscopy. A weakening of the uranyl bonds of U 60 was found while studtite, U 60 Ox 30 , and U 24 Pp 12 were relatively stable to γ-irradiation. Studtite and U 60 are the most affected by α-irradiation forming an amorphous uranyl peroxide as characterized by Raman spectroscopy and powder X-ray diffraction while U 60 Ox 30 and U 24 Pp 12 show minor signs of the formation of an amorphous uranyl peroxide.

This paper test card can identify ampicillin or amoxicillin formulations that contain <90% of the stated API content.