Iraqi National Journal Of Chemistry

A simple ,accurate and sensitive indirect spectrophotometric method for the
determination of captopril in pharmaceutical preparation(tablets) and environmental
water samples has been developed. The method is based on the oxidation of captopril
by a known excess of potassium iodate (KIO3) in sulfuric acid medium to form
iodide ion which reacts with excess iodate to liberate iodine which then reacts with
starch to form a stable blue colored Iodine-starch complex which shows maximum
absorbance at 606 nm. Beer,s law was obeyed in the concentration range ( 2-28 ppm).
The molar absorptivity and Sandell,s sensitivity of the colored complex are
1.716x104 l/mol.cm. and 12.66 ng/cm2 respectively .The analytical parameters were
optimized and the method was successfully applied to the determination of captopril
in pure form, its tablets form and environmental water samples.

New, simple and sensitive batch and Flow-injection spectrophotometric
methods for the determination of Methyldopa in pure form and in pharmaceutical
preparations were proposed. These methods were based on diazotization and coupling
reaction between methyldopa and diazotized metochlopramide in alkaline medium to
form an intense orange-red water-soluble dye that is stable and has a maximum
absorption at 470nm. A graphs of absorbance versus concentration show that Beer\'s
law is obeyed over the concentration range of 1-14 and 5-130 µg.mL-1 of Methyldopa,
with detection limits of 0.15 and 3.213 µg.mL-1 of Methyldopa for batch and FIA
methods, respectively. The FIA procedure sample throughput was 70h-1. All different
chemical and physical experimental parameters affecting on the development and
stability of the colored product were carefully studied and the proposed methods were
successfully applied to the determination of Methyldopa in pharmaceutical
preparations.

A new thiazolylazo reagent was prepared and exploited for the cloud point extraction
(CPE) methodology in the preconcentration of micro amount of Hg (II) as a prior step to its
determination by UV-Vis spectrophotometry. The extraction and determination processes of
Hg(II) involved the complexation of Hg (II) with synthesized 7-(6-Bromo 2-benzothiazolyl
azo)-8-Hydroxyquinoline (7- (6-BrBTA8HQ) at specific pH which is extracted by micelles of
the non-ionic surfactant octylphenoxypolyethoxyethanol (Triton X-114) and subsequently
detected spectrophotometrically at specific 640 nm. The optimal reaction and extraction
conditions (e.g. pH, reagent concentration, surfactant concentration, equilibrium temperature
and the incubation time) were studied and the analytical figures of merit of the method (e.g.
linearity, limit of detection, sensitivity, enrichment factor etc) were obtained. The
interferences effect of the foreigner metal ions was also considered. Under the optimum
established conditions, the enrichment factor of 123 folds was achieved which led to a
detection limit of 7.4 ng mL-1 of Hg (II) and concentration range of 8-500 ng mL-1 with
percent recovery of 100.43±1.23. The precision for seven replicate measurements of 200 ng
mL-1 Hg (II) was of 0.67%. The method was applied to the determination of mercury in some
fish samples with satisfactory results.

A simple, rapid, accurate and sensitive spectrophotometric method for the
determination of cefixime has been developed. The method is based on the formation
of the schiff’s base between the primary amino group present in cefixime and
aldehyde group present in the vanillin reagent to produce a yellow colored complex
having maximum absorption at 414 nm. Beeˈs law was obeyed over the concentration
range of 2-20µg/ml,with molar absorptivity of 8.22x104 l/mol.cm. The present
method is considered to be simple because it does not need heating, hydrolysis and
solvent extraction steps. The ingredients often formulated with cefixime have been
shown not to interfere, and is suitable for the routine determination of cefixime. The
proposed method has been successfully applied for the determination of cefixime in
pure form and in pharmaceutical preparations(capsules)

Quantitative Structure–Property Relationship (QSPR) models based on molecular
descriptors derived from molecular structures have been used for the prediction for computed
the glass transition temperatures (Tgoc) of polymer compounds. QSPR model includes some
molecular descriptors, regression quality indicates that these descriptors provide valuable
information and have significant role in the assessment of the the glass transition
temperatures (Tgoc) of polymers. Six QSPR equations for the prediction of glass transition
have been drawn up by using the multiple regression technique. (Eqs 1-6) with the values of
R2 range from 0.905-0.999, the values of Q2 range are from 0.895-0.999, and the values of S
range are from 2.585-0.127, while the values of F range from 57.570-4372.359. The results
show excellent model by Eq 6. with high of R2, Q2, F and minimum S by using six
parameters [T. E, Si15CHARGE, D. M, O14CHARGE, H. F and W. B. O], was found and indicate
that these parameters have important role in determining the properties of glass transition
temperatures (Tgoc)this result encourages the application of QSPR to a wider selection of
polymer properties and to other classes of polymers, including industrial, biopolymers.

Study of preparation involve the examination of the effects of operating variables on
mechanical properties of polylactic acid /low density polyethylene (PLA/LDPE)/clay
nanocomposites including tensile strength, modulus, and elongation at break. Thermal
stability of these nanocomposites that’s investigated. Montmorillonite clay with alkyl
ammonium ion of hexadecyl trimethylammonium bromide (CTAB) was examined. Among
the parameters studied, PLA/ LDPE nanocomposites showed larger improvements in
mechanical properties compared to PLA/ LDPE blend due to higher shear forces exerted by
polymer blend matrix on clay aggregates during polymer-clay mixing. The original MMT
with Na+ cation results in weak improvements in mechanical properties compared to
organoclays. It was observed that the tensile strength, modulus, and elongation at break of
the nanocomposite samples can be optimized with 4% of clay loading. The morphology and
chemical structure of the optimum sample were examined by X-ray diffraction and FT-IR
spectroscopy, respectively.

A number of new complexes of the general formulaes [ML2Cl2] and
[ML2(bip)]Cl2 {where L= bis-(2,3-Dimethoxybenzylidene)thiosemcarbazone ; M=
Mn(II), Fe(II),Co(II), Ni(II), Cu(II) and Zn(II),bip = bipyridyl}were prepared and
characterized by molar conductance, magnetic properties, infrared, electronic
spectra,metal contents, and CHN analysis. The electronic spectra study and magnetic
moments measurements indicated that the Mn(II), Fe(II), Co(II), Ni(II), Cu(II)and
Zn(II)complexes have an octahedral geometry.

The present study was conducted in Mosul city to show the oxidants and antioxidants
levels in different types of mature milk for (Human, buffalo, cow, sheep, goat) and compared
them with each other, beside of showing the effect of age on the composition of human breast
milk by measuring biochemical parameters which include: vitamin E, vitamin C, superoxide
dismutase (SOD), glutathione S-transferase(GST), albumin, ceruloplasmin (Cp),
glutathione(GSH), total bilirubin, uric acid, malondialdehyde (MDA), peroxynitrate(OONO-)
and the metals (Copper (Cu), zinc (Zn) and iron (Fe)). The study included (144) sample
represented in five groups according to types of milk: human milk (59 nonsmokers), buffalo
milk(19), cow milk(23), sheep milk(22) and goat milk(21) .
The results showed significant increase in vitamin E for sheep, human, cow, goat and
buffalo milk respectively, but showed significant increase for vitamin C in sheep milk and
decreased in cow milk when compared with other groups. Also SOD showed high levels in
human and goat milks, but low levels in sheep milk, while GST showed high significant
levels in buffalo and cow milk, and lower in sheep milk. The GSH observed significant
increased in human milk, but decreased in buffalo, beside of increased Cp in goat milk and
decreased in human milk.
Moreover, it has been observed that there was significant increase in uric acid, for
cow milk, but decreased in buffalo milk. On the other hand, the total bilirubin observed
significant increased in sheep milk, but decreased in cow milk. The MDA observed
significant increase in buffalo milk, but decreased in sheep milk and ONOO- levels observed
significant increased in cow milk, but decreased in buffalo when compared with other types
milk. After the determination of the elements, the results showed a significant increased in Cu
of human milk and decreased in sheep milk, while Zn levels increased significantly in buffalo
milk but decreased in human milk and iron increased significantly in cow milk but decreased
in human milk. Depending on age increasing of lactating women, mature milks were divided
into three subgroups (16-25), (26-35) and (36-42) year. It was found that vitamin E, SOD,
GSH, T.Bilir., uric acid and iron were decreased significantly for mature milk with the age
increasing for lactating women, but increased in: GST, Alb, MDA and Cu.
In conclusion, an increased antioxidants and decreased oxidants levels in: sheep milk,
goat milk, cow milk, buffalo milk and human milk respectively. On the other hand, the study
showed decreased antioxidant and increased oxidants levels in human breast milk with
increasing aging of women and that might be affected on infants health.

The present study was designed to determine the antioxidant, antibacterial and
cytotoxicity activities of the flavonoid compound (F1) extracted from Capsicum annum L.
Seeds. The compound showed greater antibacterial activity against gram positive
(Staphylococcus aureus, and Streptococcus aureus) bacteria than gram negative (Klebsiella
pneumonia, Pseudomonas aeruginosa and, E. coli) using the disc diffusion method. The
extract showed high activity against Streptococcus aureus with a zone of inhibition (40 mm)
than that of E. coli (20 mm) at a concentration of 60 mg/ml. Antioxidant, reducing power and
chelating of ferrous ion activities were also significantly higher in the flavonoid compound
(F1). It was found that these activities were increase as the extract concentration increases
(using three concentration 15 mg/ml, 30 mg/ml & 60 mg/ml, respectively). The results
showed that the flavonoid compound F1 had no cytotoxicity against the human red blood cells
in all the concentration tested (ranging between 0.5-200 ppm), by using DMSO solution as a
control.