Showing papers on "Potassium iodate published in 2006"

Application of inorganic oxidants to the spectrophotometric determination of ribavirin in bulk and capsules.

Abstract: Eight spectrophotometric methods for determination of ribavirin have been developed and validated. These methods were based on the oxidation of the drug by different inorganic oxidants: ceric ammonium sulfate, potassium permanganate, ammonium molybdate, ammonium metavanidate, chromium trioxide, potassium dichromate, potassium iodate, and potassium periodate. The oxidation reactions were performed in perchloric acid medium for ceric ammonium sulfate and in sulfuric acid medium for the other reagents. With ceric ammonium sulfate and potassium permanganate, the concentration of ribavirin in its samples was determined by measuring the decrease in the absorption intensity of the colored reagents at 315 and 525 nm, respectively. With the other reagents, the concentration of ribavirin was determined by measuring the intensity of the developed colored reaction products at the wavelengths of maximum absorbance: 675, 780, 595, 595, 475, and 475 nm for reactions with ammonium molybdate, ammonium metavanidate, chromium trioxide, potassium dichromate, potassium iodate, and potassium periodate, respectively. Different variables affecting the reaction conditions were carefully studied and optimized. Under the optimum conditions, linear relationships with good correlation coefficients (0.9984-0.9998) were found between the absorbance readings and the concentrations of ribavirin in the range of 4-1400 microg/mL. The molar absorptivities were correlated with the oxidation potential of the oxidants used. The precision of the methods were satisfactory; the values of relative standard deviation did not exceed 1.64%. The proposed methods were successfully applied to the analysis of ribavirin in pure drug material and capsules with good accuracy and precision; the recovery values were 99.2-101.2 +/- 0.48-1.30%. The results obtained using the proposed spectrophotometric methods were comparable with those obtained with the official method stated in the United States Pharmacopeia.

Spectrophotometric determination of arsenic in environmental and biological samples

Abstract: A simple and sensitive spectrophotometric method has been developed for the determination of arsenic using variamine blue as a chromogenic reagent. The method is based on the reaction of arsenic(III) with potassium iodate in acid medium to liberate iodine, which oxidizes variamine blue to form a violet coloured species having an absorption maximum at 556 nm. Beer's law is obeyed in the range 0.2-14 μg mL -1 of As(III). The molar absorptivity, Sandell's sensitivity, detection limit and quantitation limit were found to be 1.43×10 4 L mol -1 cm -1 , 5.26×10 -2 μg cm -2 , 0.022 and 0.072 μg mL -1 , respectively. The optimum reaction conditions and other analytical parameters were evaluated. The proposed method has been successfully applied for the determination of arsenic in various environmental and biological samples.

Effect of additives on rheological characteristics and quality of wheat flour parotta

Abstract: This study investigated the effects on the rheological characteristics of dough and quality of parotta (a traditional South Indian unleavened flat bread) of oxidizing agents (potassium bromate, 20 and 40 ppm; ascorbic acid, 100 and 200 ppm; and potassium iodate, 20 and 40 ppm), reducing agents (potassium metabisulfite, 100 and 200 ppm; and cysteine hydrochloride, 50 and 100 ppm), enzymes (fungal alpha-amylase, 10 and 20 ppm; and proteinase, 10 and 20 ppm) and dry gluten powder (1, 2 and 3%). Addition of oxidizing agents and dry gluten increased values for farinograph stability, extensograph and mixograph areas, apparent biaxial extensional viscosity, compressive stress, hardness and cohesiveness, while reducing agents and enzymes decreased the aforementioned characteristics and increased the force decay parameter and adhesiveness of the dough. Among the additives studied, incorporation of 100 ppm potassium metabisulfite, 50 ppm cysteine hydrochloride and 10 ppm proteinase increased the overall quality score for parotta.

[Effect of chronic mild and moderate iodine excess on thyroid anti-oxidative ability of iodine deficiency and non-iodine deficiency Wistar rats].

Abstract: OBJECTIVE To investigate the effects of chronic mild and moderate iodine excess on thyroid oxidative injury and anti-oxidative ability of iodine deficiency and non-iodine deficiency Wistar rats METHODS Four-week-old Wistar rats were fed with iodine deficient diet for three months to make iodine deficient goiter models, then divided randomly into three groups: iodine deficient control group (Group IDC) fed with double distilled water, iodine-supplement group I (Group IS I) fed with potassium iodate solutions with the iodine concentrations of 100 microg/L, and iodine-supplement group II (Group IS II), fed with potassium iodate solution with the iodine concentrations of 330 microg/L Another four-week-old Wistar rats were fed with normal diet for three months, and then divided randomly into three groups: normal control group (NC) fed with double distilled water, iodine-excess group I (IEI) fed with potassium iodate solution with the iodine concentration of 300 microg/L, and iodine-excess group II (Group IEII), fed with potassium iodate solution with the iodine concentration of 660 microg/L 1, 2, 4, 8, and 24 weeks after treatment samples of urine were collected to detect the median urine iodine (MUI), samples of plasma were collected from the hearts of 8-14 rats from each group and then rats were killed Their thyroid glands were taken out to measure the wet weight and made into homogenate Biochemical method was used to measure the activities of glutathione-peroxidase (GSH-P(X)) and superoxide dismutase (SOD) as well as the contents of malonyldialdehyde (MDA) and H2O2 in the homogenates of thyroid glands RESULTS The GSH-P(X) activity 2 weeks after treatment of Group IS II was significantly lower than that of Group IDC (P < 005), and the GSH-P(X) activity 4 weeks after treatment of Group IS I was significantly lower than that of Group IDC (P < 0001) The activities of GSH-P(X) 4, 8, and 24 weeks after treatment of Groups IS I and IS II were all lower than those of Group C at the same time points significantly (P < 0001, < 001, and < 005 respectively) The activities of SOD were decreased gradually in Groups IS I and IS II and were significantly lower than those of Group IDC since 8 weeks after treatment (P < 0001 or < 005) The SOD activities in thyroid glands of Groups IEI and IEII since 8 weeks after treatment decreased significantly in comparison with Group NC (all P < 001 or < 0001) The contents of H2O2 in thyroid glands of Groups IS I and IS II were significantly lower than those of Group IDC at different time points (P < 0001, < 001, or < 005), and were significantly lower than those of Group NC 8 and 24 weeks after treatment (P < 0001 or < 001) The contents of MDA in thyroid glands since 2 weeks after treatment of Group IEI were all significantly lower than those of Group IDC at the same time points (all P < 005), and the content of MDA in thyroid glands since 1 week after treatment of Groups IS II were all significantly lower than those of Group IDC at the same time points (all P < 005) CONCLUSION Supplementation of 100 microg/L and 330 microg/L iodine on iodine deficiency Wistar rats may alleviate the oxidative injury but weaken the anti-oxidative protection of thyroid The anti-oxidative protection of thyroid glands of non-iodine deficiency Wistar rats may also be weakened by supplementation of 300 microg/L and 660 microg/L iodine

A simple and sensitive analytical method for the determination of antimony in environmental and biological samples.

Abstract: The results of a study and application of leucocrystal violet for the determination of antimony in parts per million levels is described here. The proposed method is based on the reaction of antimony(III) with acidified potassium iodate to liberate iodine. The liberated iodine selectively oxidizes leucocrystal violet to crystal violet dye. The formed dye shows maximum absorbance at 590 nm. The color system obeys Beer's law in the concentration range from 0.4 - 3.6 µg antimony per 25 ml of final solution. The molar absorptivity and Sandell's sensitivity were found to be 7.32 × 105 l mol-1 cm-1 and 0.0016 µg cm-2, respectively. All variables were studied in order to optimize the reaction. The proposed method is satisfactorily applicable for the analysis of antimony in various environmental and biological samples. The method is simple, highly sensitive, accurate and reliable.

Estimation of iodine in salt fortified with iodine & iron

Abstract: Background & objective The National Institute of Nutrition (NIN), Hyderabad has developed double fortified salt (DFS) containing both iodine and iron to control the twin problems of iodine deficiency disorders (IDD) and iron deficiency anaemia (IDA). When the iodine content of DFS was estimated by the conventional iodometric titration using sulphuric acid (H(2)SO(4)), problems such as wide variation between duplicate analysis and under/overestimations of iodine content were encountered, which led to inconsistent results. This study was undertaken to develop a modified method for the estimation of iodine in DFS so as to get reliable iodine content of DFS. Methods A modified method was developed using orthophosphoric acid (H(3)PO(4)) and the sensitivity of the method was confirmed by estimating the iodine content of potassium iodate (KIO(3)) standard at different concentrations of iodine (0 to 100 ppm). The iodine content of DFS and iodized salt (IS) from local market and factory was estimated by the modified method as well as the conventional iodometric titration and the results were compared. Results The pH of DFS was acidic. The time gap between the additions of acid and potassium iodide (KI) played a crucial role in getting the actual iodine content of DFS. The H(2)SO(4) and ferrous sulphate (FeSO(4)) interfered with the estimation of iodine in DFS resulting in underestimation or overestimation of iodine. Modified method (H(3)PO(4)) produced consistent and reliable iodine content of DFS. Both H(2)SO(4) and H(3)PO(4) gave same results when tested with KIO(3) standard, Reference salt and IS (both experimental and purchased from local market). Actually 0.50 ml of 1 per cent KI was sufficient to estimate the iodine content of DFS or IS. Interpretation & conclusion The results of the present study showed that the conventional method using H(2)SO(4) was not suitable for the estimation of iodine in DFS. The modified method using H(2)PO(4) was ideally suited for the estimation of iodine in DFS. Also, iron from DFS did not interfere during estimation of iodine by this method. As both the conventional and the modified methods gave the same results for the iodine content of IS, it is practically prudent to use the modified method (H(2)PO(4)) for both DFS and IS instead of following one method (H(3)PO(4)) for DFS and another (H(2)SO(4)) for IS. The quantity of KI is also reduced and the order of additions of reagents is changed in the modified procedure.

Type 1 iodothyronine deiodinase activity and mRNA expression in rat thyroid tissue with different iodine intakes.

Abstract: BACKGROUND Type 1 deiodinase (D1) plays an important role in the metabolism of thyroid hormone and has close relationship with thyroid function. In this study we explore the effects of iodine intake on D1 activity and its mRNA expression and its possible mechanism. METHODS Forty-eight Wistar rats were randomly divided into six groups with 8 in each: low iodine (LI), normal iodine (NI), five-fold iodine (HI(5)), ten-fold iodine (HI(10)), fifty-fold iodine (HI(50)), one hundred-fold iodine (HI(100)) group. Three months, six months and twelve months after admistration of potassium iodate, they were sacrificed and thyroids were excised. The expression of D1 mRNA in the thyroid tissue was determined by RT-PCR and D1 activity was analyzed by (125)I-rT3 as substrate. The thyroid hormone was measured with radioimmunoassay method. RESULTS Compared with NI group, D1 mRNA expression in LI groups slightly decreased, and D1 activity greatly increased. Both T(3) and T(4) in thyroid tissue significantly decreased, but the T(3)/T(4) ratio increased. D1 mRNA expression decreased in all HI groups, and D1 activity was significantly lower in HI groups. There was a tendency of decrease in D1 activity with increased doses of iodine intakes. There was no significant difference in T(4) in thyroid tissue between HI groups and NI group, but a tendency of decrease in T(3) level was found in all HI groups. CONCLUSIONS In the case of iodine deficiency, D1 activity increased greatly in order to convert more T(4) to T(3). Excess iodine can inhibit both D1 mRNA expression and its activity to protect organism from being injured by excessive T(3).

Spectrophotometric determination of N-acetyl-L-cysteine using leucoxylenecyanol FF

Abstract: A simple and sensitive method for spectrophotometric determination of N-acetyl-L-cysteine (NAC) with leucoxylenecyanol FF (LXCFF) has been elaborated. The method is based on the following reaction sequence: NAC is oxidised with potassium iodate to the colourless product and a stoichiometric amount of I - is formed. The latter is subsequently oxidised to I 2 with the excess of potassium iodate in acidic medium. Finally, iodine oxidises LXCFF to the blue-coloured xylenecyanol FF (XCFF). Absorbance of the formed dye was measured at pH 4.0 ± 0.1 at λ max = 613 nm. The measured absorbance obeyed Beer's law over the NAC concentration range 0.2-1.6 μg mL -1 ; apparent molar absorptivity was 9.58 × 10 4 L mol-' cm-'. Optimum reaction conditions providing maximum and constant absorbance have been estimated. The proposed method has been successfully applied to the determination of NAC in pharmaceutical preparations.

Desulfurized composition for civil coal

Abstract: The invention discloses a desulfurizing composition for domestic coal, which comprises the following ingredients (by weight portions), potassium iodate 1-4, sodium chloride 7-13, calcium carbonate 50-90, rice straw ash 8-15, and calcium sulphate 30-80.

Method for preparing iodine monochloride hydrochloride solution

Abstract: FIELD: chemical industry, inorganic chemistry, chemical technology. ^ SUBSTANCE: invention relates to technology for processing mineral raw, in particular, to a method for preparing iodine monochloride hydrochloride solution. Method for preparing iodine monochloride hydrochloride solution comprises chemical interaction of iodine-containing reagent and potassium iodate in hydrochloric acid solution. Chemical interaction is carried out by continuous stirring crystalline iodine as iodine-paste and potassium iodate in hydrochloric acid solution taken in the ratio crystalline iodine : potassium iodate = (12.5:5.3)-(2.36:1.0) at the environment temperature up to the complete reaction. Invention provides enhancing the safety level of the process, reducing energy consumption, labor intensity and the cost of the end product. ^ EFFECT: improved preparing method.

Stabilized iodine monochloride as disinfecting composition

Abstract: FIELD: disinfections, biochemistry, organic synthesis for production of iodinated compounds ^ SUBSTANCE: claimed disinfecting composition with wide range bactericidal, fungicidal, and anti-viral activities contains hydrogen chloride, potassium iodide or sodium iodide; potassium iodate or sodium iodate, potassium chloride or sodium chloride in specific component ratio Alternatively composition contains calcium chloride in specific component ratio Said composition (variants) makes it possible to increase stability of iodine monochloride at low hydrochloric acid concentration (01-001 M) up to 10 month and has bactericidal activity being increased by 10 times ^ EFFECT: disinfecting composition with increased stability and bactericidal activity ^ 3 cl, 7 tbl, 8 ex