Rapid Determination of Iron in Water by Modified Thiocyanate Method

A rapid spectrophotometric method for determination of iron in water by oxidising ferrous iron with ceric ammonium sulphate at roomtemperature followed by formation of ferric thiocyanate colour complexwith potassium thiocyanate has been described. The method is simple and rapid as compared to other standard methods used in water analysis and iron content of water upto 5 ppm can be determined by this method with a maximum error of 2.8 per cen

The phytoextraction of gold and palladium from mine tailings : this thesis is presented in fulfilment of the requirements for the degree of Master of Philosophy

The extraction of gold and palladium from a South African mine tailing (Klipfontein) and artificial substrate was examined. A variety of solutions were tested and extractants observed to dissolve large quantities of metal were subsequently used in trials investigating plant uptake of gold and palladium. Extraction by thiocyanate amended with an oxidising agent dissolved large amounts of gold and palladium from the test substrates. Various combinations of thiocyanate/Fe(III) and thiocyanate/H 2 O 2 were examined. Metal extraction in the thiocyanate/Fe(III) showed dependence on redox potential and acidity of the solution; this dependence was not observed in the thiocyanate/H 2 O 2 system where production of cyanide may be an important factor. The addition of iodide to thiocyanate/Fe(III) did not affect dissolution of metals. Thiourea was also tested. This chemical was shown to be a relatively poor extractant of gold and palladium, with and without an oxidant. Two plant species, Berkheya coddii and Brassica juncea, were investigated in plant trials. Initial experiments showed uptake of metals to be independent of plant species. Greatest metal uptake was achieved using cyanide as a chemical amendment, with nearly 500 ppm gold accumulation in B. juncea planted in artificial substrate and treated with 1 gL -1 KCN every day over 6 days. Nearly 13 ppm palladium had accumulated in these plants - the highest average concentration observed with any treatment. KCN also induced the largest metal uptake from Klipfontein substrate – nearly 1600 ppb gold and 7700 ppb palladium accumulation in B. coddii. As an exercise it was shown that the value of gold and palladium that would be recovered from a phytomining operation on Klipfontein substrate would be greater than the cost of cyanide added in such an operation. Plant uptake of gold and palladium from the mine tailing after treatment with thiocyanate plus an oxidant was poor. Gold and palladium uptake by B. coddii from artificial substrate after treatment with thiocyanate + H 2 O 2 was improved, with levels of accumulation similar to that of cyanide. Metal uptake by thiocyanate + Fe(III), however, remained poor. The conclusion of this thesis is that phytomining of gold and palladium offers large potential in both practical and research terms. The relative importance of the species thiocyanate, H 2 O 2 , and cyanide remain unknown in the thiocyanate/H 2 O 2 system and further research is needed to elucidate this behaviour

One Hour of Chemical Demonstrations

This article describes a diverse set of chemistry demonstrations especially selected to encourage student interaction and to be easily transported. The demonstrations may be presented at a level that can be tailored to any audience– from very young children to high school students planning careers in science. An ideal environment is a small classroom with 20-30 students where everyone can take part in the discussion. Once the chemicals are prepared, the collection of demonstrations takes about ten minutes to set-up, and one hour (or less) to perform. Very little is needed at the visiting site, no more than a table and a pitcher of water. A single electrical outlet is useful, but not essential. In Table 2 th

Chemical enhancement of soil based footwear impressions on fabric

This study investigates the enhancement of footwear impressions prepared with soils from different locations on a variety of fabric surfaces with different morphology. Preliminary experiments using seventeen techniques were carried out and the best responding reagents were evaluated further. Results indicated that the soils investigated (a cross-section of soils from Scotland) are more likely to respond to reagents that target iron ions rather than calcium, aluminium or phosphorus ions. Furthermore, the concentration of iron and soil pH did not appear to have an effect on the performance of the enhancement techniques. For the techniques tested, colour enhancement was observed on all light coloured substrates while enhancement on dark coloured fabrics, denim and leatherette was limited due to poor contrast with the background. Of the chemical enhancement reagents tested, 2,20-dipyridil was a suitable replacement for the more common enhancement technique using potassium thiocyanate. The main advantages are the use of less toxic and flammable solvents and improved clarity and sharpness of the enhanced impression. The surface morphology of the fabrics did not have a significant effect on the enhancement ability of the reagents apart from a slight tendency for diffusion to occur on less porous fabrics such as polyester and nylon/lycra blends

Ceric and ferrous dosimeters show precision for 50-5000 rad range

Ammonium thiocyanate, added to the usual ferrous sulfate dosimeter solution, yielded a very stable, precise and temperature-independent system eight times as sensitive as the classical Fricke system in the 50 to 5000 rad range. The ceric dosimeters, promising for use in mixed radiation fields, respond nearly independently of LET

Chemical enhancement of soil-based marks on nonporous surfaces followed by gelatin lifting

This study assessed the use of processing techniques (potassium thiocyanate, 2-2-dipyridil, potassium ferrocyanide, ammonium pyrrolidinedithiocarbamate, safranin, magnetic powder) for the enhancement of soil-based marks on nonporous surfaces, followed by gelatin lifting for the recovery of these marks. Other variables in the study included the use of nonporous substrates with varying colors (ceramic tiles, glass, linoleum, plastic bags, leaflets) and different aging periods (1, 7, 14, and 28 days) prior to enhancement and gelatin lifting. A numerical grading system from -1 (deterioration) to 4 (recovery of all fine detail) was adopted to assess the quality of the enhancement achieved.In this study, the two most effective chemical enhancement techniques for soil-based marks on nonporous surfaces were safranin and potassium thiocyanate, specifically on grey linoleum and white ceramic tiles. One-day aging of soil-based marks provided poor results, whereas 28-day aging periods provided superior enhancement. In general, lifting with gelatin lifts provided further improvement on the initial enhancement, by means of contrast and sharpness. However, the use of gelatin lifting sometimes resulted in the deterioration of the original mark. Marks treated with safranin and lifted with white gelatin lifts provided even further improvement through fluorescence examination

ENHANCED METHOD FOR AMPLIFYING ANTIMICROBIAL ACTIVITY OF LACTOPEROXIDASE SYSTEM IN MILK AND DERIVED PRODUCTS BY CARROT EXTRACT AND BETA CAROTENE

OSCN–  has  been  known  and  well  documented  as  natural  antimicrobial  agent    generated  from the  lactoperoxidase  system (LPOS)  but  the  antimicrobial  activity  exerted  from  this  system  is  too  low  for  certain  food  such  as  milk  and  derived products (up to 1.2 log CFU/ml) resulting in the restriction on industrial  development  of  LPOS.  Our  previous  study  concluded  that  involvement  of  carrot  extract and beta carotene in LPOS significantly boosted the antimicrobial activity  (up  to  6  log  CFU/ml)  against  S.  enteritidis.  This  finding  should  be  continued  to  the  application  on  food.  Since  we  found  that  LPOS  generates  low  antimicrobial  activity  on  milk  and  derived  product,  our  research  will  be  conducted  on  the  application  of  LPOS  plus  carrot  extract  and  beta  carotene  on  milk  and  derived  product.  Because  the  high  antimicrobial  activity  is  needed  for  industrial  purposes,  this  research  may  open  the  way  for  industrial  development  of  natural  antimicrobial agent from LPOS.  This research will be conducted in three steps of experiment: (1) ensuring  the  incredible  antimicrobial  activity  of  LPOS  plus  carrot  extract  and  beta  carotene  against  three  poisonous  tropical bacteria:  C. jejuni,  S. enteritidis,  and E.  coli,  (2)  utilization  of  LPOS  plus  carrot  extract  and  beta  carotene  in  milk:  full  cream and skimmed milk, and (3) utilization of LPOS plus carrot extract and beta  carotene  in  milk  derived  product:  yogurt  and  tropical  fruity  milk.  The  purification  of  LPO  from  bovine  milk,  the  complimentary  data  analysis  for  generation  of  LPOS  antimicrobial  activity  by  the  addition  of  carrot  extract  and  beta  carotene  will  be  conducted  in  Japan  and  for  the  application  in  tropical  poisonous  bacteria,  milk,  and  milk  derived  product  will  be  conducted  in  Indonesia.  The  outcomes  of  this  research  from  three  step  of  research  are  three  international  publications  at  international‐scopus‐indexed‐journals  :  International Journal of  Dairy Science and  one  of  patent:  “enhanced  method  for  improvement of LPOS antimicrobial activity by involvement of carrot extract and  beta carotene in milk and derived product”.     Keywords:  Lactoperoxidase,  antimicrobial  activity,  carrot  extract,  beta  carotene,  milk, derived products

STUDIES ON ANTIOXIDANT ACTIVITIES OF SIX CULTIVARS OF PIPER BETLE LINN

Objective: To study the existence of difference or similarity on total phenolic content, flavonoid content and antioxidant properties among different cultivars of Piper betle L. Methods: The methanolic extracts of six different cultivars, i. e. Banarasi, Bangla, Calcutta, Kammar, Kumbakonam and Vellai were evaluated for total phenolic content (Folin-Ciocalteu method), total flavonoid content (Aluminium chloride method), total antioxidants (Phospho-molybdenum method) and other antioxidant properties (TBA assay, Ferric thiocyanate assay, FRAP assay and ABTS assay). Results: Total phenolic content of the cultivars ranges from 12.5 to 13.9 mg TAE/g DW. Higher flavonoid content was observed in Kumbakonam (24.14 µg QE/g DW) while Bangla possessed the lowest (8.25 µg QE/g DW). The total antioxidants of Vellai accounted to 58.82 mg TAE/g DW while the lowest was recorded in Kumbakonam (39.34 mg TAE/g DW). Maximum % inhibition was observed in the cultivar Vellai for Ferric thiocyanate (FTC), Kumbakonam for Thiobarbituric acid (TBA) and Banarasi for Ferric Reducing Antioxidant Power (FRAP). However, no significant difference was exhibited among the cultivars for ABTS assay. Conclusion: The study amply demonstrates the existence of difference in total phenolic content, total flavonoids and antioxidant property. Thus, proper selection of cultivar of Piper betle for specific use in the pharmaceutical industry is recommended