Simple, accurate and reliable spectrophotometric method
has been developed for the quantitative determination of
Cephalosporins: Cefaclor, Cefalexin, Cefadroxil in pure and
pharmaceutical formulations. The method is based on the
determination of that in aqueous medium pH=6.45 at
25±0.5ºC.
A Simple, accurate and highly sensitive spectrophotometric method have been
developed for the rapid determination of Ofloxacine (OFX) in pure form and
pharmaceutical formulations. The visible spectrophotometric method was based on the
formation of
a Orange Yellow colored complex between the (OFX) and 2-amino-6-
nitrobenzothiazole (ANB) at pH 5.2 and 80±5 ºC in 5 min., and λmax at 440 nm. The
effects of analytical parameters on the reported system were investigated. Beer's law was
obeyed in the concentration range of 1.80-86.72 μg/mL, with a percentage relative standard
deviation not exceed ±2.54 and the molar absorptivity coefficients was 3.952×103
(L/mol.cm). Interferences of the other ingredients and excipients were not observed, the
results showed that the developed method with the accuracy and sensitivity highs.
There are wide uses of tin oxide thin films, especially in the field of
transparent conductors, solar cells, gas sensors and piezoelectric materials.
Laser deposition is considered one of the most important techniques followed to
obtain these film
s. In this research, we develop a technique to obtain
homogeneous thin films of tin oxide depending on vaporization of pile targets of
this oxide by continuous CO2 laser in the atmosphere, with a fan which
guarantees obtaining homogenous films. Some of these films were annealed in
different conditions. The optical microscope images revealed the presence of
high degree of homogeneity, while the X-Ray study showed different
crystallization grain orientations which depend on the preparation conditions.
The preferred direction is (110). The optical absorption gives information
about the value of the effective band gal for the samples before and after
thermal annealing. We have found that some films have Eg = 3.2 ev. before
annealing, and after long annealing they have Eg=1.3ev. In addition, the hard
annealed thin films reveal anisotropy in the optical and electrical.
Characteristics, they have different absorption coefficients in two
perpendicular directions, also there is an electrical resistance anisotropy along
these two directions especially after hard annealing. The Eb was 0.73 ev before
annealing, it became 0.37 ev for one direction and 0.32 ev for the other
direction.
