Two high-performance liquid chromatography (HPLC) methods for ascorbic acid (AA) quantification were compared in three cultivars of melon (Cucumis melo L.) fruits. Both procedures were analogous except for the extraction medium used: 6 % meta-phosphoric acid and 3 % citric acid. The general conclusion is that 3 % citric acid is a better extraction medium compared to 6 % meta-phosphoric acid and...

OBJECTIVES This study evaluated the effect of etching using 2% proanthocynidin-containing 10% phosphoric acid 2% PA/10% PhA vs. 35% phosphoric acid 35% PhA on immediate (IM) and 6-months (6M) resin-enamel microshear bond strength (μSBS), resin-dentin microtensile bond strength (μTBS), nanoleakage (NL) and as well as in situ MMP inhibition potential. METHODS The dentin surface of human were ex...

Key words iridium catalysis - chiral phosphoric acid photocatalyst 2+2 cycloaddition

Key words phosphoric acid - deprotection tert-butoxycarbonyl group peptide synthesis

In a previous report (1) the isolation, toxicity and some chemical data concerning the lipopolysaccharide endotoxin of Neisseria gonorrhoeae was described. The present investigation includes the following: (a) an improved modification of lipopolysaccharide phosphoric acid ester preparation; (b) hydrolysis of lipopolysaccharide phosphoric acid ester and removal of fatty acids; (c) separation of ...

The present work deals with enzymatic hydrolysis of sweet sorghum bagasse to fermentable sugars. The bagasse was treated with phosphoric acid and sodium hydroxide prior to enzymatic hydrolysis by commercial cellulase and β-glucosidase. The phosphoric acid pretreatment was performed at 50°C for 30 min, while 12% NaOH was used for the alkali treatment at 0°C for 3 h. The phosphoric acid pretreatm...

abstract mefenamic acid is a nonsteroidal anti-inflammatory drug (nsaid) that has analgesic,anti-infammatory and antipyretic actions. it is used to relieve mild to moderate pains. solid-phase extraction of mefenamic acid by a polymer grafted to silica gel is reported . poly allyl glycidyl ether/iminodiacetic acid-co-n, n-dimethylacrylamide was synthesized and grafted to silica gel and was used ...

introduction in this study, we have investigated the effect of using phosphoric acid on bonding efficacy of an all-in-one adhesive system, after salivary contamination of dentin. methods and materials eighty-four extracted human molars were prepared for their superficial dentins to be exposed. the molars separated into 7 groups. group 1 specimens were not contaminated. in groups 2-4, samples we...