Studying of the Nitrate Contamination in Coriander Plant in Dezful, Khouzestan, Iran

ABSTRACT: In recent years, there has been much attention to the amount of nitrate. Nitrate is not toxic for animals and human. However, if nitrate reduces to nitrite, it can combine with hemoglobin and form met-hemoglobin. Regarding the importance of this subject, they present research was conducted to study the situation of coriander in terms of nitrate contamination in vegetable farms in Dezful city. Samples were collected from vegetable farms located in northern, southern, eastern and western areas of Dezful, twice a day, in the morning and afternoon, randomly from the first, middle and last rows of the farms. After the samples had been washed with distilled water, they were ground and dried in and oven in 65 ° C. Then their moisture percent was determined. The samples were ground twice using an electric grinder and after weighing the extraction of anion nitrate using distilled water, a certain amount of the sample was tested. After being shaking, the extract was separated by centrifuge and nitro sulfusalicylic complex was formed using solution like. Then it was read by spectrophotometer in wave length 410 nm in front of standard solution. Duncan test with probability level of 5% and spss software version 18 were applied to compare mean and standard deviation of nitrate concentration in samples from the areas under study. Results of analyses indicated that the highest amount of nitrate was seen in the north farm samples of Dezful. Results of statistical analysis revealed significant difference between nitrate amounts in areas under study. Moreover, nitrate concentration was reported more than permitted in coriander. As well, nitrate concentration tested in the morning and afternoon samples showed significant difference and the highest difference was related to north of Dezful. Therefore, in order to obtain low levels of nitrate concentration, considering soil Analysis, organic cultivation, consuming organic and biologic fertilizers, micronutrients and eugenics can be regarded. Because of its high consumption and great changes in nitrate concentration in coriander, further in investigation and continuous control of nitrate concentration is necessary.