The determination of nimodipine in the presence of its degradation products, formed through photolysis, acidic and alkaline hydrolysis, and the drug degradation kinetics under these conditions, was investigated through a validated liquid chromatography method. Separation was achieved using a Phenomenex Luna C18 column (250 × 4.6 mm i.d., 5 µm) with a mobile phase consisting of acetonitrile-meth...

UV photolysis is an effective process to remove nitrosamines from contaminated water resources.

Direct ultraviolet (UV) photolysis coupled with modification of solution pH was explored as a method for the removal of organic micropollutants from groundwater. Photodegradation rates of most of the investigated compounds were pH dependent, however, its correlation with photodegradation rate varied among compounds. The potential of the pH modification during photolysis was determined for remov...

Secondary organic aerosol (SOA) particles are generated by reacting d-limonene vapor and ozone in a Teflon reaction chamber. The reaction is carried out in either dry or humid air in darkness. The resulting SOA particles are collected on glass fiber filters, and their photochemical properties are probed using a combination of UV photodissociation action spectroscopy and absorption spectroscopy ...

Photolysis of rat adrenocortical cells in the presence of the photoreactive derivative [(2-nitro-5-azidophenylsulfenyl)Trp9]-adrenocorticotropic hormone (2,5-NAPS-ACTH) at 24 degrees C resulted in persistent activation of corticosterone production. The basal rate of steroidogenesis became maximal when photolysis was performed at 24 degrees C but remained the same as that of control cells when i...

The photodegradation rate of sulphadimethoxine (SMT) in water was studied under polychromatic UV light, in a bench scale apparatus. SMT photolysis was carried out at pH levels of 2.5, 6.5 and 10 to study the impact of acid base properties on the degradation of SMT. The highest SMT photolysis fluence based rate was found at pH=2.5 (k=7.22x10(-4) cm2/mJ) and the lowest rate at pH=10 (k=4.72x10(-4...

Picosecond time-resolved resonance Raman (ps-TR3) spectroscopy was used to obtain the first definitive spectroscopic observation of an isopolyhalomethane O-H insertion reaction with water. The ps-TR3 spectra show that isobromoform is produced within several picoseconds after photolysis of CHBr3 and then reacts on the hundreds of picosecond time scale with water to produce a CHBr2OH reaction pro...

Resonance-enhanced multiphoton ionization coupled with time-of-flight product imaging has been used to study the O2(Σg) + O(Pj) product channel in the UV photodissociation of ozone at photolysis wavelengths of 226, 230, 240, and 266 nm. For dissociation at 226 and 230 nm the O(P2) fragment is produced with a strongly bimodal velocity distribution, in keeping with the previous findings of Miller...

The photosensitised degradation of 4-chlorophenol (4-CP) by iron meso-tetrakis(2,6-dichloro-3-sulfophenyl)porphyrin (FeTDCPPS) has been studied in aerated aqueous solution, and is shown to lead to formation of p-benzoquinone (BQ) and p-hydroquinone (HQ) as main photoproducts. In deaerated solution no p-benzoquinone was formed. The photolysis products were identified by high performance liquid c...