RESONANCE RAMAN INVESTIGATION OF PH-DEPENDENT EQUILIBRIA OF WATER-SOLUBLE IRON PORPHYRINS

Resonance Raman spectroscopy has been used to probe the structures of; tetrakis(1-methylpyridinium-4-yl)-porphinatoiron(III), FeIII (T4MPyP); tetrakis(1-methylpyridium-2-yl)porphinatoiron(III), FeIII (T2MPyP); tetrakis(4-sulphonatophkenyl)porphinatoir(III), FeIII(TSPP); and tetrakis(4-carboxylatophenyl)porphinatoiron(III), FeIII(TCPP), over a wide pH range. The anionic complexes FeIII (TSPP) and FeIII (TCPP) contain high-spin iron(III) at all pHs. Both these complexes exhibit marked spectral changes at ca. pH 6 which correspond to conversion from the diaquo species, in acid solution, to hydroxy- or mu-oxo dimer complexes. Both cationic complexes show similar diaquo to high-spin hydroxy, or mu-oxo dimer, transitions at ca. pH 6. However, at pH > 11.5 for FeIII (T4MPyP) and pH > 9 for FeIII (T2MPyP) a second equilibrium process is observed, leading to two new species. One of these is readily assigned as the low-spin iron(III) dihydroxy complex by analogy with spectra of the dicyano complex. The second species is assigned to the hydroxy iron(II) complex by comparison with photo-chemically generated FeII (T4MPyP) (OH). The formation of iron(II) species in alkaline solutions of FeIII (T4MPyP) and FeIII (T2MPyP) is entirely unexpected and the significance of the observation to previous investigations of the pH-dependent behaviour of these complexes is discussed.

Arsenic sequestration in iron plaque, its accumulation and speciation in mature rice plants (Oryza sativa L.)

A compartmented soil-glass bead culture system was used to investigate characteristics of iron plaque and arsenic accumulation and speciation in mature rice plants with different capacities of forming iron plaque on their roots. X-ray absorption near-edge structure spectra and extended X-ray absorption fine structure were utilized to identify the mineralogical characteristics of iron plaque and arsenic sequestration in plaque on the rice roots. Iron plaque was dominated by (oxyhydr)oxides, which were composed of ferrihydrite (81-100%), with a minor amount of goethite (19%) fitted in one of the samples. Sequential extraction and XANES data showed that arsenic in iron plaque was sequestered mainly with amorphous and crystalline iron (oxyhydr)oxides, and that arsenate was the predominant species. There was significant variation in iron plaque formation between genotypes, and the distribution of arsenic in different components of mature rice plants followed the following order: iron plaque > root > straw > husk > grain for all genotypes. Arsenic accumulation in grain differed significantly among genotypes. Inorganic arsenic and dimethylarsinic acid (DMA) were the main arsenic species in rice grain for six genotypes, and there were large genotypic differences in levels of DMA and inorganic arsenic in grain.

Influence of a pore-forming agent on swelling, network parameters, and permeability of poly(ethylene glycol)-crosslinked poly(methyl vinyl ether-co-maleic acid) hydrogels:Application in transdermal delivery systems

We characterized hydrogels, prepared from aqueous blends of poly(methyl vinyl ether-co-maleic acid) (PMVE/MA) and poly(ethylene glycol) (PEG 10,000 Daltons) containing a pore-forming agent (sodium bicarbonate, NaHCO ). Increase in NaHCO content increased the equilibrium water content (EWC) and average molecular weight between crosslinks (M ) of hydrogels. For example, the %EWC was 731, 860, 1109, and 7536% and the M was 8.26, 31.64, 30.04, and 3010.00 × 10 g/mol for hydrogels prepared from aqueous blends containing 0, 1, 2, and 5% w/w of NaHCO , respectively. Increase in NaHCO content also resulted in increased permeation of insulin. After 24 h, percentage permeation was 0.94, 3.68, and 25.71% across hydrogel membranes prepared from aqueous blends containing 0, 2, and 5% w/w of NaHCO , respectively. Hydrogels containing the pore-forming agent were fabricated into microneedles (MNs) for transdermal drug delivery applications by integrating the MNs with insulin-loaded patches. It was observed that the mean amount of insulin permeating across neonatal porcine skin in vitro was 20.62% and 52.48% from hydrogel MNs prepared from aqueous blends containing 0 and 5% w/w of NaHCO . We believe that these pore-forming hydrogels are likely to prove extremely useful for applications in transdermal drug delivery of biomolecules. © 2012 Wiley Periodicals, Inc.

Catalytic conversion of sodium lignosulphonate to vanillin –engineering aspects. Part 1 Effect of processing conditionson vanillin yield and selectivity

The commercial production of vanillin from sodium lignosulfonate under highly alkaline conditions, catalyzed by Cu2+ at elevated temperature and pressures up to 10 bar, has been simulated in a 3-L stirred reactor. Initially, the process was operated in the presence of nitrogen in dead-end mode, and it was shown that vanillin and vanillic acid were formed by hydrolysis at temperatures of 120, 140, and 160 °C. At the two higher temperatures, the amount of vanillin produced was the same. Subsequently, experiments were conducted at the same elevated pressures and temperatures with addition of air or oxygen-enriched air once the temperature in the reactor had reached temperatures similar to those used when only hydrolysis occurred. In this case, the concentration of vanillin at 140 and 160 °C was equal to that due to hydrolysis, and the subsequent 2-fold increase was due to oxidation. In addition, both vanillic acid and acetovanillone (which has rarely been reported) were produced, as was hydrogen. Thus, for the first time, it has been shown that the production of vanillin (and other compounds) from sodium lignosulfonate at elevated temperatures involves hydrolysis and oxidation, with hydrolysis starting at just above 100 °C, that is, much lower than has previously been reported. Approximately 50% is produced by each mechanism. In addition, the orders of the reactions of the different steps were estimated, and the reaction mechanisms are discussed.

Iron plaque formation, arsenic uptake and speciation in different genotypes of mature rice plants (Oryza sativa L.)

A compartmented soil-glass bead culture system was used to investigate characteristics of iron plaque and arsenic accumulation and speciation in mature rice plants with different capacities of forming iron plaque on their roots. X-ray absorption near-edge structure spectra and extended X-ray absorption fine structure were utilized to identify the mineralogical characteristics of iron plaque and arsenic sequestration in plaque on the rice roots. Iron plaque was dominated by (oxyhydr)oxides, which were composed of ferrihydrite (81-100%), with a minor amount of goethite (19%) fitted in one of the samples. Sequential extraction and XANES data showed that arsenic in iron plaque was sequestered mainly with amorphous and crystalline iron (oxyhydr)oxides, and that arsenate was the predominant species. There was significant variation in iron plaque formation between genotypes, and the distribution of arsenic in different components of mature rice plants followed the following order:? iron plaque > root > straw > husk > grain for all genotypes. Arsenic accumulation in grain differed significantly among genotypes. Inorganic arsenic and dimethylarsinic acid (DMA) were the main arsenic species in rice grain for six genotypes, and there were large genotypic differences in levels of DMA and inorganic arsenic in grain. A compartmented soil-glass bead culture system was used to investigate characteristics of iron plaque and arsenic accumulation and speciation in mature rice plants with different capacities of forming iron plaque on their roots. X-ray absorption near-edge structure spectra and extended X-ray absorption fine structure were utilized to identify the mineralogical characteristics of iron plaque and arsenic sequestration in plaque on the rice roots. Iron plaque was dominated by (oxyhydr)oxides, which were composed of ferrihydrite (81-100%), with a minor amount of goethite (19%) fitted in one of the samples. Sequential extraction and XANES data showed that arsenic in iron plaque was sequestered mainly with amorphous and crystalline iron (oxyhydr)oxides, and that arsenate was the predominant species. There was significant variation in iron plaque formation between genotypes, and the distribution of arsenic in different components of mature rice plants followed the following order:? iron plaque > root > straw > husk > grain for all genotypes. Arsenic accumulation in grain differed significantly among genotypes. Inorganic arsenic and dimethylarsinic acid (DMA) were the main arsenic species in rice grain for six genotypes, and there were large genotypic differences in levels of DMA and inorganic arsenic in grain.

Rifampicin and sodium fusidate reduces the frequency of methicillin-resistant Staphylococcus aureus (MRSA) isolation in adults with cystic fibrosis and chronic MRSA infection

Nosocomial transmission of methicillin-resistant Staphylococcus aureus (MRSA) to patients with cystic fibrosis (CF) frequently results in chronic respiratory tract carriage. This is an increasing problem, adds to the burden of glycopeptide antibiotic use in hospitals, and represents a relative contraindication to lung transplantation. The aim of this study was to determine whether it is possible to eradicate MRSA with prolonged oral combination antibiotics, and whether this treatment is associated with improved clinical status. Adult CF patients (six male, one female) with chronic MRSA infection were treated for six months with rifampicin and sodium fusidate. Outcome data were examined for six months before treatment, on treatment and after treatment. The patients had a mean age of 29.3 (standard deviation=6.3) years and FEV(1) of 36.1% (standard deviation=12.7) predicted. The mean duration of MRSA isolation was 31 months. MRSA isolates identified in these patients was of the same lineage as the known endemic strain at the hospital when assessed by pulsed-field gel electrophoresis. Five of the seven had no evidence of MRSA during and for at least six months after rifampicin and sodium fusidate. The proportion of sputum samples positive for MRSA was lower during the six months of treatment (0.13) and after treatment (0.19) compared with before treatment (0.85) (P<0.0001). There was a reduction in the number of days of intravenous antibiotics per six months with 20.3+/-17.6 on treatment compared with 50.7 before treatment and 33.0 after treatment (P=0.02). There was no change in lung function. Gastrointestinal side effects occurred in three, but led to therapy cessation in only one patient. Despite the use of antibiotics with anti-staphylococcal activity for treatment of respiratory exacerbation, MRSA infection persists. MRSA can be eradicated from the sputum of patients with CF and chronic MRSA carriage by using rifampicin and sodium fusidate for six months. This finding was associated with a significant reduction in the duration of intravenous antibiotic treatment during therapy.

Engineered MRI nanoprobes based on superparamagnetic iron oxide nanoparticles

This project aimed to engineer new T2 MRI contrast agents for cell labeling based on formulations containing monodisperse iron oxide magnetic nanoparticles (MNP) coated with natural and synthetic polymers. Monodisperse MNP capped with hydrophobic ligands were synthesized by a thermal decomposition method, and further stabilized in aqueous media with citric acid or meso-2,3-dimercaptosuccinic acid (DMSA) through a ligand exchange reaction. Hydrophilic MNP-DMSA, with optimal hydrodynamic size distribution, colloidal stability and magnetic properties, were used for further functionalization with different coating materials. A covalent coupling strategy was devised to bind the biopolymer gum Arabic (GA) onto MNPDMSA and produce an efficient contrast agent, which enhanced cellular uptake in human colorectal carcinoma cells (HCT116 cell line) compared to uncoated MNP-DMSA. A similar protocol was employed to coat MNP-DMSA with a novel biopolymer produced by a biotechnological process, the exopolysaccharide (EPS) Fucopol. Similar to MNP-DMSA-GA, MNP-DMSA-EPS improved cellular uptake in HCT116 cells compared to MNP-DMSA. However, MNP-DMSA-EPS were particularly efficient towards the neural stem/progenitor cell line ReNcell VM, for which a better iron dose-dependent MRI contrast enhancement was obtained at low iron concentrations and short incubation times. A combination of synthetic and biological coating materials was also explored in this project, to design a dynamic tumortargeting nanoprobe activated by the acidic pH of tumors. The pH-dependent affinity pair neutravidin/iminobiotin, was combined in a multilayer architecture with the synthetic polymers poy-L-lysine and poly(ethylene glycol) and yielded an efficient MRI nanoprobe with ability to distinguish cells cultured in acidic pH conditions form cells cultured in physiological pH conditions.

Metabolic and respiratory effects of infused sodium acetate in healthy human subjects.

The metabolic and respiratory effects of intravenous 0.5 M sodium acetate (at a rate of 2.5 mmol/min during 120 min) were studied in nine normal human subjects. O2 consumption (VO2) and CO2 production (VCO2) were measured continuously by open-circuit indirect calorimetry. VO2 increased from 251 +/- 9 to 281 +/- 9 ml/min (P < 0.001), energy expenditure increased from 4.95 +/- 0.17 kJ/min baseline to 5.58 +/- 0.16 kJ/min (P < 0.001), and VCO2 decreased nonsignificantly (211 +/- 7 ml/min vs. 202 +/- 7 ml/min, NS). The extrapulmonary CO2 loss (i.e., bicarbonate generation and excretion) was estimated at 48 +/- 5 ml/min. This observation is consistent with 1 mol of bicarbonate generated from 1 mol of acetate metabolized. Alveolar ventilation decreased from 3.5 +/- 0.2 l/min basal to 3.1 +/- 0.2 l/min (P < 0.001). The minute ventilation (VE) to VO2 ratio decreased from 22.9 +/- 1.3 to 17.6 +/- 0.9 l/l (P < 0.005), arterial PO2 decreased from 93.2 +/- 1.9 to 78.7 +/- 1.6 mmHg (P < 0.0001), arterial PCO2 increased from 39.2 +/- 0.7 to 42.1 +/- 1.1 mmHg (P < 0.0001), pH from 7.40 +/- 0.005 to 7.50 +/- 0.007 (P < 0.005), and arterial bicarbonate concentration from 24.2 +/- 0.7 to 32.9 +/- 1.1 (P < 0.0001). These observations indicate that sodium acetate infusion results in substantial extrapulmonary CO2 loss, which leads to a relative decrease of total and alveolar ventilation.

Postglacial paleoecology and effects of European settlement on the environment of Lake Hunger and Lake Lisgar, Southwestern Ontario /

This investigation has three purposes I to make a comparative chemical study on sediment cores collected for Lake Lisgar (man-made lake in an urban center) and Lake Hunger (natural basin in a rural community) encompassing the time since European settlement I to determine the postglacial chemical history of Lake Hunger, and to determine the vegetational history of the Lake Hunger area from postglacial time to the present. The minus 80 mesh fraction of 108 soil samples and 18 stream sediment samples collected in the vicinity of Lakes' Lisgar and Hunger were analyzed for cold hydrochloric acid soluble lead, zinc, nickel, cobalt, copper, aluminum, sodium, potassium, calcium, magnesium, iron and manganese. Lacustrine sediments from 5 boreholes in the Lake Lisgar basin were collected. Boreholes 1, 2, 3, and 4 were analyzed for palynological and chemical information and Borehole 5 was subjected to pollen and ostracode analysis. Lacustrine sediments from 6 boreholes in the Lake Hunger basin were collected. Palyno- -logical and chemical analysis were performed on Boreholes 1, 2, 3, 4, and 6 and Borehole 5 was analyzed for pollen. In addition, radiocarbon dates were obtained on sediment samples from Boreholes 4 and 5. A total of 8 surface samples were collected from the margins of the Lake Hunger basin and these were chemically analyzed in the laboratory. All of the lacustrine sediments were ashed and analyzed for cold hydrochloric acid soluble lead, zinc, nickel, cobalt, copper, aluminum, sodium, potassium, calcium, magnesium, iron and manganese using a Perkin Elmer 40) Atomic Absorption spectrophotometer. The results . obtained for the 12 elements were expressed as parts per million in dry sediments. It was found that man's influence on the element distribution patterns in the sediments of Lake Lisgar appeared to be related to his urbanizing developments within the lake vicinity, whereas, the rural developments in the vicinity of lake Hunger appeared to have had little effect on the element distribution patterns in the lake sediments. The distribution patterns of lead, zinc, nickel, cobalt, aluminum, magnesium, sodium and potassium are similar to the % ash curve throughout postglacial time indicating that the rate of erosion in the drainage basin is the main factor which controls the concentration of these elements in the sediments of Lake Hunger. The vegetational history, from palynological analysis, of Lake Hunger from postglacial time to the present includes the following stages: tundra, open spruce forest, closed boreal forest, deciduous forest and the trend towards the re-establishment of pine following the clearing of land and the subsequent settlement of the Lake Hunger area by European settlers. The concentrations of some elements (cobalt, nickel, iron, manganese, calcium, magnesium, sodium and potassium) in the sediments of Lake Hunger appears to be higher during pre-cultural compared to post-cultural times. At least one complete postglacial record of the chemical history within a lake basin is necessary in order to accurately assess man's effects on his environment.

Half-sandwich silane complexes of ruthenium and iron : synthesis, structure and application to catalysis

The present thesis describes syntheses, structural studies, and catalytic reactivity of new non-classical silane complexes of ruthenium and iron. The ruthenium complexes CpRu(PPri3)CI(T]2-HSiR3) (1) (SiR3 = SiCh (a), SiClzMe (b), SiCIMe2 (c), SiH2Ph (d), SiMe2Ph (e» were prepared by reactions of the new unsaturated complex CpRu(PPri3)CI with silanes. According to NMR studies and X-ray analyses, the complexes la-c exhibit unusual simultaneous Si··· H and Si··· CI-Ru interactions. The complex CpRu(PPri3)CI was also used for the preparation of the first examples of late transition metal agostic silylamido complexes CpRu(PPri3)(N(T]2-HSiMe2)R) (2) (R= Ar or But), which were characterized by NMR spectroscopy. The iron complexes CpFe(PMePri2)H2(SiR3) (3) (SiR3 = SiCh (a), SiClzMe (b), SiCIMe2 (c), SiH2Ph (d), SiMe2Ph (e» were synthesized by the reaction of the new borohydride iron complex CpFe(PMePri2)(B~) with silanes in the presence NEt3. The complexes 3 exhibit unprecedented two simultaneous and equivalent Si··· H interactions, which was confirmed by X-ray analyses and DFT calculations. A series of cationic ruthenium complexes [CpRu(PR3)(CH3CN)(112-HSiR'3)]BAF (PR3 = PPri 3 (4), PPh3 (5); SiR'3 = SiCh (a), SiClzMe (b), SiClMe2 (c), SiH2Ph (d), SiMe2Ph (e» was obtained by substitution of one of the labile acetonitrile ligands in [CpRu(PR3)(CH3CNh]BAF with sHanes. Analogous complexes [TpRu(PR3)(CH3CN)(T]2 -HSiR' 3)]BAF (5) were obtained by the reaction of TpRu(PR3)(CH3CN)CI with LiBAF in the presence of silanes. The complexes 4-5 were characterized by NMR spectroscopy, and the observed coupling constants J(Si-H) allowed us to estimate the extent of Si-H bond activation in these compounds. The catalytic activity in hydrosilylation reactions of all of the above complexes was examined. The most promising results were achieved with the cationic ruthenium precatalyst [CpRu(PPri3)(CH3CN)2t (6). Complex 6 shows good to excellent catalytic activity in the hydrosilylation of carbonyls, dehydrogenative coupling of silanes with alcohols, amines, acids, and reduction of acid chlorides. We also discovered very selective reduction of nitriles and pyridines into the corresponding N-silyl imines and l,4-dihydropyridines, respectively, at room temperature with the possibility of catalyst recycling. These chemoselective catalytic methods have no analogues in the literature. The reactions were proposed to proceed via an ionic mechanism with intermediate formation of the silane a-complexes 4.

The Synthesis of Imidazole Fatty Acid Conjugates as Inhibitors of Apoptosis

Ionizing radiation is known to initiate apoptosis in mammalian cells by causing the transformation of cytochrome c into a peroxidase, which results in the specific peroxidation of the mitochondrial phospholipid cardiolipin. Here we report the design and synthesis of 8 imidazole fatty acid derivatives that bind to the cyt c:CL complex and inhibit the peroxidase activity required for the initiation of apoptosis. We postulate that imidazole acts as a sixth ligand to the haem iron and stops the interaction with H2O2. Two mitochondrially directed analogues (3-hydroxypropyl)triphenylphosphonium esters) of 12-imidazole-stearic acid and 12-imidazole-oleic acid not only were demonstrated to be peroxidase inhibitors in vitro, but were also extraordinarily effective in protecting mice from lethal doses (9 Gy) of ionization radiation. We studied the structure activity relationship to a group of triphenyl phosphonium derivatives containing imidazole at different positions on the fatty acid chain, and observed that the C8-imidazole stearate analogue had marginally better activity than the others. But overall, the structure activity result were remarkable “flat” with all compounds prepared having rather similar inhibitory strength. We also synthesized carnitine mono and di-esters of 12-imidazole fatty acids but full biological data is not yet available for these compounds.

Utilisation des suppléments alimentaires chez les athlètes d’élite québécois

Ce projet découle du Canadian Sport Centre Dietary Study qui avait pour objectif d’évaluer les habitudes de consommation de suppléments alimentaires chez les athlètes canadiens et de déterminer si des différences régionales existaient. Un nombre de sujets était prédéterminé pour chaque province en considération du nombre d’athlètes identifiés comme Excellence, Élite ou Relève par les Centres d’entraînement nationaux et les organismes gouvernementaux. Pour ce mémoire, seules les données associées aux athlètes du Québec ont été considérées. Quarante-trois athlètes ont répondu à un questionnaire sur l’utilisation des suppléments alimentaires, 71 ont fourni un journal alimentaire de trois jours et 42 parmi ces derniers ont remis les deux documents. La prévalence d’utilisation des suppléments alimentaires était de 90,7%. Les utilisateurs consommaient en moyenne 3,35 produits différents, particulièrement des boissons énergétiques (48,8%), des multivitamines-minéraux (37,2%), des produits de santé naturels (37,2%) et des suppléments de protéines en poudre (34,9%). Les athlètes souhaitaient maintenir leur santé (27,9%) et améliorer leur niveau d’énergie (27,9%) ou leur récupération (25,6%). Les sources d’information citées étaient les entraîneurs physiques (25,6%), la famille ou les amis (16,3%) et les coéquipiers (16,3%). Les sujets se procuraient ces produits dans les épiceries (16,3%), les pharmacies (14,0%) et les magasins spécialisés (9,3%). Soixante-dix pour cent des sujets croyaient que l’arrêt de l’utilisation des suppléments alimentaires n’aurait aucun impact sur leurs performances ou ne savaient pas comment cela les influencerait. Ils démontraient un vif intérêt au sujet de l’efficacité (69,8%), la légalité (55,8%) et la sécurité (53,5%) de ces produits. Des sujets qui utilisaient un supplément de protéines, 81% présentaient un apport alimentaire supérieur à leurs besoins. L’utilisation de suppléments de multivitaminesminéraux permettait de combler l’apport insuffisant en calcium et en folate, mais pas en potassium. Nos résultats soulignent que ces utilisateurs présentaient des apports dépassant l’apport maximal tolérable pour le sodium, le magnésium, la niacine, le folate, la vitamine A et le fer. Nous pouvons donc conclure que ces deux types de suppléments alimentaires n’étaient pas utilisés d’une façon pertinente.

Lactide polymerization with iron alkoxide complexes

Les essais préliminaires pour préparer des alcoolates de fer à partir du bichlorure ou bibromure de fer (II), en les combinant avec des ligands de type diimino pyridine, ont engendré la formation de complexes homoleptiques et hétéroleptiques, dépendant des substituants sur les branches imines du ligand. Ces complexes homoleptiques octaédriques et paramagnétiques ont été étudiés par rapport à leurs propriétés spectroscopiques et cristallographiques. De plus, la synthèse des complexes de fer hétéroleptique a engendré de bons précurseurs penta-coordonnés pour les réactions de substitution de ligands avec des alcoolates de métaux alcalins, de manière à produire les dialcoolates de fer (II) désirés. Des techniques d’analyse telles que la spectroscopie UV-vis, l’analyse élémentaire, la spectrométrie de masse à haute résolution et la cristallographie aux rayons X ont été utilisées pour caractériser ces complexes de fer. L’activité catalytique de ces complexes de fer (II) a aussi été étudiée par rapport à la polymérisation du lactide; les dialcoolates convoités ont été générés in-situ en raison de la difficulté à produire et à isoler les dérivés alcoolates des complexes diimino pyridine de fer. Une étude approfondie a aussi été faite sur les réactions de polymérisation, surtout par rapport aux valeurs de conversion à l’échelle du temps, ainsi qu’à la tacticité des chaines de polymères obtenues. Ces analyses ont été effectuées par l’entremise de la spectroscopie de résonance magnétique nucléaire, de la chromatographie d’exclusion stérique, et de la spectrométrie de masse MALDI (désorption-ionisation laser assistée par matrice).

Spectrophotometric Methods for the Determination of Cafotaxime Sodium In Dosage Forms

Two simple and sensitive spectrophotometric methods(A and B) in the visible region have been developed for the determination of cefotaxime sodium (DFTS) in bulk and in dosage forms. Method A is based on the reaction of CFTS with nitrous acid under alkaline conditions to form a stable violet colored chromogen with absorption maximum of 560 nm and method B is based on the reaction of CFTS with1,10-phenanthroline and ferric chloride to form a red colored chromogen with the absorption maximum of 520 mm.The color obeyed Beer’s law in the concentration range of 100-500 µg/ml for method A and 1.6-16 µg/ml for method B, respectively.When pharmaceutical preparations containing CFTS were analysed, the results obtained by the proposed methods are in good agreement with the labeled amounts and are comparable with the results obtained using a UV spectrophotometric method.

Sorptional Behaviour of Metals on the Sediments and Humic acid of Mangrove Ecosystem

Humic substances are complex polymeric structures.No other polymers with such a wide range of properties are so widely distributed in nature.But still their moleculer structures are unknown. A structural knowledge is essential in determining their reactivity with metals.In the present work structural elucidation of humic acids from three different mangrove ecosystems of Cochin area is done with the available data from functional group analysis and various spectroscopic methods.13C NMR spectra of the solid samples with CPMAS,IR and SEM are very promising in revealing the complex structures of these polymeric substances.Sorptional studies on the sediment and humic acid of mangrove ecosystem reveals that the major portion of the organic matter is not extractable with Sodium hydroxide and humic acid only a small portion of the total organic matter. Humic acid is a good complexing agent and scavenger. Due to the nonextractable nature of the organic matter present with the sediment left after alkali extraction it is a better scavenger.