How big is the substituent dependence of the solar photolysis rate of Criegee intermediates?

2018 ◽  
Vol 20 (23) ◽  
pp. 16247-16255 ◽  
Author(s):  
Cangtao Yin ◽  
Kaito Takahashi
Keyword(s):  
Uv Spectra ◽  
Photolysis Rate ◽  
Criegee Intermediates ◽  
Solar Photolysis ◽  
Multireference Methods

Substituent dependence of the UV spectra of Criegee intermediates were calculated using multireference methods.

Pharmaceutically Active Compounds Degradation Using Doped TiO2 Functionalized Zeolite Photocatalyst

2018 ◽  
Vol 69 (1) ◽  
pp. 34-37 ◽  
Author(s):  
Monica Ihos ◽  
Corneliu Bogatu ◽  
Carmen Lazau ◽  
Florica Manea ◽  
Rodica Pode
Keyword(s):  
Organic Carbon ◽  
Active Compound ◽  
Uv Spectra ◽  
Pharmaceutically Active Compounds ◽  
Mineralization Process ◽  
Active Compounds ◽  
Spectra Analysis ◽  
Doped Tio2 ◽  
Toc Removal ◽  
Pharmaceutically Active Compound

The aim of this study was the investigation of photocatalytic degradation of pharmaceutically active compounds using doped TiO2 functionalized zeolite photocatalyst. Diclofenac (DCF), a non-steroidal anti-inflammatory drug, that represents a biorefractory micropollutant, was chosen as model of pharmaceutically active compound. The photocatalyst was Z-TiO2-Ag. The concentration of DCF in the working solutions was 10 mg/L,50 mg/L,100 mg/L and 200 mg/L and of photocatalyst 1 g/L in any experiments. The process was monitored by recording the UV spectra of the treated solutions and total organic carbon (TOC) determination. The UV spectra analysis and TOC removal proved that along the advanced degradation of DCF also a mineralization process occurred. The carried out research provided useful information envisaging the treatment of pharmaceutical effluents by photocatalysis.

Comparison of UV- and Derivative-Spectrophotometric and HPTLC UVDensitometric Methods for the Determination of Amrinone and Milrinone in Bulk Drugs

2020 ◽  
Vol 16 (3) ◽  
pp. 246-253
Author(s):  
Marcin Gackowski ◽  
Marcin Koba ◽  
Stefan Kruszewski
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
High Performance ◽  
Low Cost ◽  
Uv Spectra ◽  
Derivative Spectrophotometry ◽  
Therapeutic Monitoring ◽  
Bulk Drug ◽  
Layer Chromatography ◽  
Standard Solutions

Background: Spectrophotometry and thin layer chromatography have been commonly applied in pharmaceutical analysis for many years due to low cost, simplicity and short time of execution. Moreover, the latest modifications including automation of those methods have made them very effective and easy to perform, therefore, the new UV- and derivative spectrophotometry as well as high performance thin layer chromatography UV-densitometric (HPTLC) methods for the routine estimation of amrinone and milrinone in pharmaceutical formulation have been developed and compared in this work since European Pharmacopoeia 9.0 has yet incorporated in an analytical monograph a method for quantification of those compounds. Methods: For the first method the best conditions for quantification were achieved by measuring the lengths between two extrema (peak-to-peak amplitudes) 252 and 277 nm in UV spectra of standard solutions of amrinone and a signal at 288 nm of the first derivative spectra of standard solutions of milrinone. The linearity between D252-277 signal and concentration of amironone and 1D288 signal of milrinone in the same range of 5.0-25.0 μg ml/ml in DMSO:methanol (1:3 v/v) solutions presents the square correlation coefficient (r2) of 0,9997 and 0.9991, respectively. The second method was founded on HPTLC on silica plates, 1,4-dioxane:hexane (100:1.5) as a mobile phase and densitometric scanning at 252 nm for amrinone and at 271 nm for milrinone. Results: The assays were linear over the concentration range of 0,25-5.0 μg per spot (r2=0,9959) and 0,25-10.0 μg per spot (r2=0,9970) for amrinone and milrinone, respectively. The mean recoveries percentage were 99.81 and 100,34 for amrinone as well as 99,58 and 99.46 for milrinone, obtained with spectrophotometry and HPTLC, respectively. Conclusion: The comparison between two elaborated methods leads to the conclusion that UV and derivative spectrophotometry is more precise and gives better recovery, and that is why it should be applied for routine estimation of amrinone and milrinone in bulk drug, pharmaceutical forms and for therapeutic monitoring of the drug.

Syntheses, spectral properties and pesticide activity of O-ethyl-S-propyl-O-(1-alkyl, phenyl-5-chloro, alkoxy-6-oxo-1H-pyridazine-4-yl)esters of dithiophosphoric acid

1980 ◽  
Vol 45 (8) ◽  
pp. 2247-2253 ◽  
Author(s):  
Václav Konečný ◽  
Štefan Varkonda ◽  
Vojtech Kubala
Keyword(s):  
Spectral Properties ◽  
Uv Spectra ◽  
Dithiophosphoric Acid ◽  
Insecticide Activity ◽  
Ir And Uv Spectra

Syntheses of O-ethyl-S-propyl-O-(1-alkyl, phenyl-5-chloro, alkoxy-6-oxo-1H-pyridazine-4-yl) esters of dithiophosphoric acid are described. The compounds were investigated for their IR and UV spectra and for their contact and system activities as insecticides, acaricides, ovicides, fungicides and herbicides. Some of the compounds proved efficient acaricides; compound VIII also had an insecticide activity.

Thermal cyclocondensations of 3-N(4- and 5-benzimidazolyl and benztriazolyl)amino derivatives of 2-propenoic acid

1987 ◽  
Vol 52 (12) ◽  
pp. 2918-2925 ◽  
Author(s):  
Viktor Milata ◽  
Dušan Ilavský
Keyword(s):  
Uv Spectra ◽  
Propenoic Acid ◽  
Amino Derivatives ◽  
Derivatives Of ◽  
C Nmr ◽  
Ir And Uv Spectra

The cyclization of 3-N(4- and 5-benzimidazolyl and benztriazolyl)amino-2-cyano- and 2-ethoxycarbonyl-2-propenoate esters Ia, b-IVa, b under the conditions of the Gould-Jacobs reaction leads to angularly ring-fused substituted imidazo or triazolo[4,5-f] (V, VI) and [4,5-h] (VII, VIII) quinolines, respectively. The esters Vb-VIIIb have been transformed into the corresponding chloroderivatives Vc-VIIIc. 3-N(5-Benzimidazolyl and 5-benztriazolyl)amino-2-cyano-2-propenenitriles are cyclized in the presence of aluminium(III) chloride to give the aminoquinolines Vd, VId. The structure of the products has been characterized by their 1H, 13C NMR, IR, and UV spectra.

Ribonuclease a catalyzed preparative synthesis of dinucleoside monophosphates containing uridine analogues

1980 ◽  
Vol 45 (2) ◽  
pp. 611-616 ◽  
Author(s):  
Antonina P. Kavunenko ◽  
Antonín Holý
Keyword(s):  
Paper Chromatography ◽  
Ribonuclease A ◽  
Uv Spectra ◽  
Preparative Synthesis ◽  
Cyclic Phosphate ◽  
Dinucleoside Monophosphates

Preparative synthesis of dinucleoside monophosphates, catalyzed by ribonuclease A, is described. Uridine 2',3' -cyclic phosphate was used as a donor, the acceptors being uridine (Ia), N3-methyl-uridine (Ib), 5-methyluridine (Ic), 6-methyluridine (Id), 3-(β-D-ribofuranosyl)uracil (IIa), 1-methyl-3-(β-D-ribofuranosyl)uracil (IIb), 6-azauridine (III) and 6-methyl-2'-deoxyuridine (IV). The obtained compounds of the type UpN (where N is the nucleoside moiety I-IV) were characterized by paper chromatography, electrophoresis and UV-spectra.

Photoreaction of N-butyl 3,4-dimethoxy-6-nitrobenzamide with butylamine. A model study for lysine-directed photoaffinity labelling

1987 ◽  
Vol 52 (7) ◽  
pp. 1780-1785 ◽  
Author(s):  
Petr Kuzmič ◽  
Libuše Pavlíčková ◽  
Milan Souček
Keyword(s):  
Nitro Group ◽  
Aromatic Ring ◽  
Ultraviolet Irradiation ◽  
Title Compound ◽  
Reductive Coupling ◽  
Photoaffinity Labelling ◽  
Photolysis Rate ◽  
Model Study ◽  
A Minor

Ultraviolet irradiation of the title compound I in the presence of butylamine gave predominantly products of nucleophilic photosubstitution by the amine, i.e., nitroanilines IIa and IIb. Besides, small amounts of products of hydrolysis (phenol III) and reductive coupling (azoxybenzene IV) were also formed. Comparison of the overall photolysis rate of I with that of 3,4-dimethoxy-1-nitrobenzene (V) indicates a minor loss of reactivity, most probably due to some deviation from coplanarity of the activating nitro group and the aromatic ring.

Separation and Determination of Some Aromatic Sulfones by Reversed-Phase High-Performance Liquid Chromatography

1994 ◽  
Vol 59 (3) ◽  
pp. 569-574 ◽  
Author(s):  
Josef Královský ◽  
Marta Kalhousová ◽  
Petr Šlosar
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Mobile Phase ◽  
High Performance ◽  
Reversed Phase ◽  
Uv Spectra ◽  
Optimum Conditions ◽  
Linear Calibration ◽  
Technical Grade

The reversed-phase high-performance liquid chromatography of some selected, industrially important aromatic sulfones has been investigated. The chromatographic behaviour of three groups of aromatic sulfones has been studied. The optimum conditions of separation and UV spectra of the sulfones and some of their hydroxy and benzyloxy derivatives are presented. The dependences of capacity factors vs methanol content in mobile phase are mentioned. The results obtained have been applied to the quantitative analysis of different technical-grade samples and isomer mixtures. For all the separation methods mentioned the concentration ranges of linear calibration curves have been determined.

scholarly journals Quantifying the Effects of Vibration on Medicines in Transit Caused by Fixed-Wing and Multi-Copter Drones

Drones ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 22
Author(s):  
Andrew Oakey ◽  
Tim Waters ◽  
Wanqing Zhu ◽  
Paul G. Royall ◽  
Tom Cherrett ◽  
...  
Keyword(s):  
Road Transport ◽  
Uv Spectra ◽  
Frequency Spectra ◽  
Vibration Measurements ◽  
British Pharmacopoeia ◽  
Medical Products ◽  
Industry Standard ◽  
The Stability ◽  
In Transit

The concept of transporting medical products by drone is gaining a lot of interest amongst the medical and logistics communities. Such innovation has generated several questions, a key one being the potential effects of flight on the stability of medical products. The aims of this study were to quantify the vibration present within drone flight, study its effect on the quality of the medical insulin through live flight trials, and compare the effects of vibration from drone flight with traditional road transport. Three trials took place in which insulin ampoules and mock blood stocks were transported to site and flown using industry standard packaging by a fixed-wing or a multi-copter drone. Triaxial vibration measurements were acquired, both in-flight and during road transit, from which overall levels and frequency spectra were derived. British Pharmacopeia quality tests were undertaken in which the UV spectra of the flown insulin samples were compared to controls of known turbidity. In-flight vibration levels in both the drone types exceeded road induced levels by up to a factor of three, and predominant vibration occurred at significantly higher frequencies. Flown samples gave clear insulin solutions that met the British Pharmacopoeia specification, and no aggregation of insulin was detected.

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