Report Ld 50 of Cockroaches
Pharmacology Report 1: Determination of an insecticide in cockroaches
Introduction
Pesticides are toxic and go through many different testings and procedures before they are put on the shelf in various industries. One general method that is used to asses toxicity of pesticides before released for sale is the LD50 (Lethal Dose 50) method. This method is conducted by calculating the most accurate dose of toxin that will kill animals 50% of the time. Before determining an accurate LD50 of a chemical however, a range finding analysis of the chemical will be performed in order to calculate the most accurate LD50. Undergoing this procedure includes using a wide-spread range of concentrations which are mostly preformed at log dose intervals. (H.P. Rang, M.M. Dale, J.M. Ritter and R.J. Flower, 2007).
Carbamate Propoxur is an insecticide that can inhibit the action of cholinesterase and disrupt nervous system function (Extension Toxicology network, Pesticide Information Profiles; http://extoxnet.orst.edu/pips/propoxur.htm). In this experiment propoxur was used to investigate the effects on the American cockroach nymphs.
The LD50 for one species is very different from another. In each LD50 test there is considerations that need to be understood such as age, weight, sex, health and diet (David Rall, Ph.D., former Director, National Toxicology Program “Inadequacy of the LD50 test” Found at http://www.pcrm.org/resch/anexp/LD50.htm). Each individual factor cannot be accurately monitored for each individual animal if randomly acquired. This is only one of the reasons why the LD50 test is not quite useful as it does not maintain a biological constant and that value therefore has little significance in testing toxicity.
Methodology
Refer to practical manual; however note change in purity of propoxur to 99.5% hence 0.2513g was used and also the use of 12 cups of 5 cockroaches making total number of nymphs used 60
Results
Table 1.1
This table shows the procedure
Introduction
Pesticides are toxic and go through many different testings and procedures before they are put on the shelf in various industries. One general method that is used to asses toxicity of pesticides before released for sale is the LD50 (Lethal Dose 50) method. This method is conducted by calculating the most accurate dose of toxin that will kill animals 50% of the time. Before determining an accurate LD50 of a chemical however, a range finding analysis of the chemical will be performed in order to calculate the most accurate LD50. Undergoing this procedure includes using a wide-spread range of concentrations which are mostly preformed at log dose intervals. (H.P. Rang, M.M. Dale, J.M. Ritter and R.J. Flower, 2007).
Carbamate Propoxur is an insecticide that can inhibit the action of cholinesterase and disrupt nervous system function (Extension Toxicology network, Pesticide Information Profiles; http://extoxnet.orst.edu/pips/propoxur.htm). In this experiment propoxur was used to investigate the effects on the American cockroach nymphs.
The LD50 for one species is very different from another. In each LD50 test there is considerations that need to be understood such as age, weight, sex, health and diet (David Rall, Ph.D., former Director, National Toxicology Program “Inadequacy of the LD50 test” Found at http://www.pcrm.org/resch/anexp/LD50.htm). Each individual factor cannot be accurately monitored for each individual animal if randomly acquired. This is only one of the reasons why the LD50 test is not quite useful as it does not maintain a biological constant and that value therefore has little significance in testing toxicity.
Methodology
Refer to practical manual; however note change in purity of propoxur to 99.5% hence 0.2513g was used and also the use of 12 cups of 5 cockroaches making total number of nymphs used 60
Results
Table 1.1
This table shows the procedure
Bibliography: * H.P. Rang, M.M. Dale, J.M. Ritter and R.J. Flower, 2007 * Ullmann’s Agrochemicals, Volume 1, edited by wiley-VCH, LASTWiley-VCH pages 691-695