Home About us Contact
|
Home About us Contact | ||
|
|
||
Diatomaceous Earth (diatomaceous + earth)
Selected AbstractsDiatomaceous earths as alternatives to chemical insecticides in stored grainINSECT SCIENCE, Issue 6 2006AMIN NIKPAY Abstract Diatomaceous earth (DE) is a natural inert dust used to control insect pests in stored grain as an alternative to synthetic residual insecticides. Various DE formulations are now registered as a grain protectant or for structural treatment in many different countries throughout the world. The mode of action of DE is through the absorption of cuticular waxes in the insect cuticle, and insect death occurs from desiccation. The main advantages of using DE are its low mammalian toxicity and its stability. The main limitations to widespread commercial use of DE are reduction of the bulk density and flowability of grain, irritant hazards during application and reduction in efficacy at high moisture contents. This paper is an updated review of published results of researches related to the use of DEs and discusses their potential use in large-scale, commercial storage and in small scale applications. [source] Effect of five diatomaceous earth formulations against Tribolium castaneum (Coleoptera: Tenebrionidae), Oryzaephilus surinamensis (Coleoptera: Silvanidae) and Rhyzopertha dominica (Coleoptera: Bostrychidae)INSECT SCIENCE, Issue 5 2007MASUMEH ZIAEE Abstract Laboratory bioassays were conducted to determine the effect of food source on the survival of Tribolium castaneum Herbst, Oryzaephilus surinamensis L. and Rhyzopertha dominica F., after exposure to five diatomaceous earth (DE) formulations: Protect-It®, Insecto®, Perma-GuardŌ, Dryacide® and SilicoSec®. Adults of these species were exposed to DEs at the rate of 0.5 mg/cm2 for 1 day on filter paper inside plastic Petri dishes. After exposure, the initial mortality was counted and live individuals of the three species were held for a week in glass vials containing 50 mg wheat flour, rice and whole wheat, respectively. In the second experiment, after 1 day exposure to DEs, beetles were transferred to Petri dishes without food and held for a week to determine if the presence of food source would decrease the mortality of beetles. Experiments were carried out at 27°C and 55% RH in the dark. The initial mortality in both of the experiments reached 100% for the three species exposed to Protect-It® and in the case of R. dominica and O. surinamensis exposed to Dryacide®. In contrast, low level of mortality (< 10%) was observed for T. castaneum exposed to Perma-GuardŌ and Insecto®. The mortality after the post-treatment period on food was decreased for the three species exposed to Perma-GuardŌ and in the case of T. castaneum and R. dominica exposed to Insecto® and SilicoSec®. Adults of O. surinamensis were the most susceptible followed by R. dominica and 100% adult mortality was obtained, whereas T. castaneum were the least susceptible beetles to DEs. Protect-It® and Dryacide® were the most efficient DE formulations and can be used effectively in a stored grain integrated pest management program. [source] Persistence and efficacy of two diatomaceous earth formulations and a mixture of diatomaceous earth with natural pyrethrum against Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae) on wheat and maizePEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 5 2006Basileios J Vayias Abstract Laboratory tests were conducted to assess the insecticidal and residual effects of three diatomaceous earth (DE) formulations, Insecto®, PyriSec® and SilicoSec®, against Tribolium confusum Jacquelin du Val on wheat and maize. Quantities of wheat and maize were treated with the above formulations at 500, 1000 and 1500 mg kg,1 and stored at 25 °C and 55% relative humidity (RH). Samples were taken on the day of storage and every 30 days until completion of a 360 day period of storage. Adults of T. confusum were exposed to these samples at 25 °C and 55% RH and the mortality was measured after 24 and 48 h and 7 and 14 days of exposure. Adult mortality was higher on wheat than on maize. At the beginning of the storage period, mortalities after 14 day exposure on maize treated with the highest rate were 60, 63 and 81% for Insecto®, PyriSec® and SilicoSec® respectively, while on wheat the mortality was 100% for all DEs. On the same commodities 360 days after treatment the respective mortality figures for wheat were 99, 98 and 100%, while in the case of maize they did not exceed 7%. Generally, mortality at exposures ,48 h decreased with increasing storage time. Furthermore, although mortality on wheat increased with dose, the increase in DE dose from 1000 to 1500 mg kg,1 resulted in only a small increase in mortality. Thus a DE treatment of 1000 mg kg,1 was shown to provide long-term protection of wheat against T. confusum, although higher DE application rates and exposure intervals are needed for a satisfactory level of protection of maize against this pest. Copyright © 2006 Society of Chemical Industry [source] Automated method for measuring globin adducts of acrylamide and glycidamide at optimized Edman reaction conditions,RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 6 2006Hubert W. Vesper The general population is exposed to acrylamide, a potential human carcinogen, through food and cigarette smoke. The assessment of human exposure to acrylamide is important in the evaluation of health risks associated with this chemical. Hemoglobin adducts of acrylamide (AA-Hb) and its primary metabolite glycidamide (GA-Hb) are established biomarkers of acrylamide exposure and methods to measure these biomarkers using modified Edman reaction are described. Only limited information about the optimal Edman reaction conditions such as pH or temperature is available for these adducts and the existing methods do not allow automation needed in biomonitoring studies. In this study, the yield of Edman products of AA-Hb and GA-Hb between pH 3,10 and at 35,55°C at different time intervals, and the applicability of liquid-liquid extraction on diatomaceous earth for analyte extraction, were assessed and results were used in a new optimized method. The applicability of our optimized method was assessed by comparing results obtained with a convenience sample from 96 individuals with a conventional method. Maximum yield of Edman products was obtained between pH 6,7, heating the reaction solution at 55°C for 2,h resulted in the same yields as with conventional conditions, and use of diatomaceous earth was found suitable for automated analyte extraction. Using these conditions, no difference was observed between our optimized and a conventional method. The median globin adduct values in the convenience sample are 129,pmol/g globin (range: 27,453,pmol/g globin) and 97,pmol/g globin (range: 27,240,pmol/g globin) for AA-Hb and GA-Hb, respectively. The GA-Hb/AA-Hb ratio decreases significantly with increasing AA-Hb values indicating that measurement of AA-Hb as well as GA-Hb are needed to appropriately assess human exposure to acrylamide. Published in 2006 by John Wiley & Sons, Ltd. [source] Carbohydrate utilization by juvenile silver perch, Bidyanus bidyanus (Mitchell).AQUACULTURE RESEARCH, Issue 2 2003Abstract The ability of juvenile silver perch (Bidyanus bidyanus) to utilize dietary raw wheat meal, raw wheat starch, gelatinized wheat starch and dextrin as energy sources to spare protein for growth was quantified. Energy utilization and protein sparing were assessed by comparing the weight gain, energy retention efficiency, protein retention and body composition of silver perch that had been fed a series of diets in which the basal diet (low carbohydrate) was systematically replaced with graded levels of each carbohydrate ingredient or an inert diluent, diatomaceous earth. The protein content decreased as the carbohydrate content increased, giving four different protein to energy ratios for each of the four carbohydrate sources (except for the 60% inclusion level, at which only three carbohydrate sources were tested). Silver perch were efficient at utilizing carbohydrate for energy to spare protein. Silver perch fed diets containing up to 30% wheat meal, raw wheat starch, gelatinized wheat starch or dextrin exhibited similar growth, protein retention and energy retention efficiency to the fish fed the basal diet. Weight gain of silver perch fed diets containing wheat meal or carbohydrates at 45% inclusion content had significantly reduced weight gain when compared with fish fed the basal diet. However, protein retention and energy retention efficiency were similar or better. Whole-body protein levels of silver perch remained constant regardless of carbohydrate sources, and there was no evidence of increasing whole-body lipid concentrations for fish fed diets with up to 60% dietary carbohydrate. Silver perch were more efficient at utilizing processed starch (either gelatinized starch or dextrin) than wheat meal or raw wheat starch. [source] Removal of pesticides from red and white wine by the use of fining and filter agentsAUSTRALIAN JOURNAL OF GRAPE AND WINE RESEARCH, Issue 1 2004GREG A. RUEDIGER Abstract Effects of the use of the fining and filtration agents, diatomaceous earth, bentonite, polyvinylpoly-pyrrolidone and activated carbon, on the removal of seven fungicides (carbendazim, chlorothalonil, fenarimol, metalaxyl, oxadixyl, procymidone and triadimenol) and three insecticides (carbaryl, chlorpyrifos and dicofol) from wines were investigated. Carbendazim was determined by high performance liquid chromatography (HPLC) after quantitative conversion into 2-aminobenzimidazole (2AB). The concentrations of all the other compounds in wine were quantified using a multi residue assay involving solid phase extraction (SPE) and gas chromatography-mass spectrometry (GC-MS). After treatment and processing, conducted under conditions simulating those that are typical in Australian commercial winemaking, the greatest reduction in concentration in all treatments was for chlorothalonil, chlorpyrifos and dicofol. There was a significant relationship between the extent of removal of each pesticide and its solubility in wine, such that the lower the solubility, the greater the extent of removal. Activated carbon had the largest effect on the removal of most pesticides, while bentonite had a major effect on the removal of carbendazim. For all compounds and agents, the rate of removal was greater in white wine than in red wine. [source] | ||||||||||