This study was conducted in Lattakia Governorate (Burj Islam Village) to study the level of contamination of the greenhouses soil with the two organic phosphorous pesticides Dimethoate and Dichlorovos. The optimal wavelength was determined for the an
alysis of both pesticides using High Performance Liquid Chromatography (HPLC) technology with UV/DAD detector. According to the results, the optimal wavelength for the analysis of Dimethoate is 200 nm, while it was 195 nm for the analysis of Dichlorovos. The recovery of Dimethoate was estimated at wavelength 200 nm which was 101.33 ± 3.868 and for dichlorvos at wavelength 195 nm when it was 98.995 ± 2.078. The results also showed that the greenhouses soil were contaminated with the residues of both pesticides, Dimethoate was detected in concentrations between (0.839 - 2.668) ppm, while Dichlorovos concentrations were between (10.046 - 44.359) ppm, indicating extensive use of both especially Dichlorovos, whose concentrations were higher than Dimethoate's in the studied sites.
The purpose of this article is how to determine simultaneously the content of
some Anti-Inflammatory (NSAIDS):, Ketoprofen, Flurbiprofen, Orphenadrine
Citrate (Muscle relaxant( and Clopidogrel Bisulfate (Anti-thrombocytopenia( in
pure and pharmace
utical formulations by Reverse Phase-High performance liquid
chromatography (RP-HPLC).
The present study describes a simple stability-indicating reversed-phase HPLC assay
for pentoxifylline in its pharmaceutical dosage forms. Separation of the drug and the
degradation products، under stress conditions was successfully achieved on a C
18 column
utilizing water: MeOH (60:40 v/v)، pumped at a flow rate of 1 ml min-1 with UV detection
at 272 nm. The retention time of pentoxifylline was about 14 min. The method was
satisfactorily validated with respect to linearity، precision، accuracy and selectivity. The
response was linear in the range of 0.6-3.5 μg/ml with R2 0.994. The method was accurate
(recovery 100.1%) and precise (RSD < 2%). Detection and quantification limit were 0.2
μg/ml and 0.4 μg/ml respectively. The suggested method was successfully applied for the
analysis of pentoxifylline in extended release tablets available in Syrian market.
A new analytical method has proposed for determination of
five synthetic colorants used in the wine industry (i.e., Tartrazine,
Brilliant Black, Sunset yellow, Brilliant Blue and Erythrosine) by
reversed-phase high-performance liquid chromatograph
y equipped
with Diode Array detector.
Experimental conditions, including spectral properties, limits
of detection and recoveries for these synthetic colorants in detail
were studied and assigned according to the statistical methods
adopted.
The possibility to develop a High-Performance Liquid
Chromatographic method was studied for simultaneous
determination of: Cu(II), Ni(II), Co(II), Hg(II) by using DTC as
reagent. The diethyldithiocorbamate Reagent was studied by
spectrophotometric Method, Unique Ionisation Constant was
determined and its value.
Herbal slimming products are one of the most wide spreading herbal products in many countries around the world and in Syria as well, they are often advertised to contain purely natural ingredients. These products are provided by various sources and t
hey are available over the counter, therefore, in most cases, they are not under quality control. Such these quality-uncontrolled products are considered a health and economic issue facing many countries in the world especially undeveloped countries which usually lack for regulation rules governing herbal products trading. In this study, 20 samples have been collected from the herbal slimming products available in the local market. At the beginning, these samples have been divided into locally manufactured samples (8 samples) and illegal samples (12 samples). The packaging and labeling test has been applied to all samples. Later on, these samples have been tested with TLC and HPLC to make sure they are free of Sibutramine, using in TLC Methanol/Toluene (1:9) as a mobile phase, and in HPLC Acetonitrile/phosphate buffer pH=5.5 (70:30) as a mobile phase, column BDS Hypersil C18, flow rate 0.5 ml/min and wavelength 225nm. The results of packaging and labeling test revealed that all of the locally manufactured samples are matching to the American pharmacopoeia USP30 and GMP in terms of packaging, labeling and internal leaf sheets with exception for one sample. As for illegal samples, all of them matched the pharmacopoeia and GMP with exception for 6 samples. With regards to testing the samples using TLC and HPLC, results indicated that 3 samples out of 8 locally manufactured samples contained Sibutramine with amount ranging between (8- 10) mg/capsule, while all illegal samples contained Sibutramine with amount ranging between (5-26) mg/capsule.
Carotenoids were separated from the wild type yeast
R.mucilaginosa (A23) and its UV mutant at (254 nm)
R.mucilaginosa (A23-M) using thin layer chromatography
(TLC).The results showed the wild type yeast gave three color
patches, β-Carotene,Torule
ne and Torularhodin with Rf values of
0.9, 0.7 and 0.2 respectively, while the mutant yeast gave only one
spot of color ofTorularhodin at thethe value of Rf = 0.2. Carotenoid
produced by mutant yeast R.mucilaginosa (A23-M) was purified
using a column stocked with polychlorinated Hyflo Super Cel and
magnesium oxide with a ratio of (1: 2). The purified carotenoid was
analyzed by high performance liquid technology chromatography
HPLC at a wavelength 495 nm showing that there was only one
colored compound which was Torularhodin
Tylosin and Spiramycin are medium-spectrum macrolide antibiotic used exclusively in veterinary medicine for the treatment of a wide range of infections.This research deals with the determination of optimal conditions for simultaneous separation and d
etermination of two macrolides antibiotics (Tylosin and Spyramicine), using C8 and C18 Chromatographic separation columns and doing the comparison between them in order to develop a rapid and sensitive method which can be used to measure these two compounds using High Performance Liquid Chromatography – Diode array detector (HPLC-DAD).
This study has used the gradient elution for mobile phase and revealed that the best conditions for separation and determination are conjugated with the best retention times and best areas for both studied compounds using a mobile phase consisted of an aqueous solution of anhydrated disodium Hydrogen Phosphate at pH=2.4 and an organic solution of acetonitrile with a ratio of 80:20v/v (solution A) and acetonitrile (solution B) [Na2HPO4(0.04M) pH:2.4/CAN (80:20v/v)]/ ACN, temperature 40°C for both columns, flow ratio of 1ml/min. for the mobile phase and maximum absorption wave length 280 nm, 232nm for Tylosin and Spyramicine respectively. The best peak areas are recorded as 5.759, 5.927 for Tylosin and Spyramicine 0.10ppm respectively, using C8 Chromatographic separation column in comparison with the best peak areas 4.432, 4.212 respectively at the same concentration using C18 Chromatographic separation column. It was noticed that the best retention times for Tylosin and Spyramicine were 7.013, 4.214min. respectively at concentration of 0.10ppm using C8 Chromatographic separation column in comparison with the best retention times 7.641, 5.898min. respectively at the same concentration using C18 Chromatographic separation column. The calibration curves for both separated compounds on C8 Chromatographic separation column showed a good linearity within a concentration range of 0.0010-0.10 ppm ≈ 1-100ppb at the two wave lengths λmax. = 280, 232nm respectively.
The purpose of this article is how to use HPLC technique for
quantitive analysis of cholesterol in some foods. The best conditions
are studied for this analysis including composition of mobile phase,
temperature, flow rate, the wavelength of detec
tor UV-VIS, and
acidity of mobile phase. The column used for cholesterol
determination by this method was: C18(5μm,250x4.6mm) with
injection volume of 20μL. Methanol 100% was used as mobile
phase.
spectrophotometric and chromatographic methods was used for
determination of five water-soluble vitamins, including : Thiamine
HCl (B1), Ascorbic acid (VC), Niacinamide (PP), Cyanocobalamin
(B12), Riboflavin (B2) in this research.
The conditions
of chromatographic separation were reached to the
vitamins with good resolution.
