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Honey is a natural substance produced by honeybees and flower nectar. It has complex compounds such as carbohydrates (fructose and glucose), phenols, organic acids, amino acids, proteins, minerals, vitamins and lipids. Organophosphorus pesticides, as diazinon, are used more than other pesticides due to their effect on a wide range of pests and also cheap price. It is noteworthy that diazinon is in category 2 in the classification of the World Health Organization and is considered as a relatively hazardous pesticide. In this regard, in the present study, the amount of residue of diazinon in honey produced in Damavand region was measured with the aim of providing the health of consumers and preparing the ground for qualitative control of this product. The honey samples used in this study were prepared from six areas of Ayeneh Varzan, Aro, Havir, Mosha, Tar Lake and Damavand in June and September. Then, the separation and detection of toxin were done by HPLC. According to the results, the residue of toxin was observed in all sampling areas so that in some areas the amount of residual was higher than the maximum residue level (MRL). Also, the residue in June in all samples was more than the samples harvested in September. In this regard, the highest amount of residue was measured in June in Ayeneh Varzan (0.03919 ppm) and its lowest amount was measured in September in Havir region with the amount of 0.1714 ppm.

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Abstract
Honey is a supersaturated solution that contains fructose and glucose. Honey also contains minerals, proteins, amino acids, enzymes and vitamins. There is a wide range of partial compounds in honey that many of them have antioxidant properties. These compounds include phenolic acids and flavonoids, some enzymes (glucose oxidase, catalase) and amino acids. Fluvalinate is an insecticide, acaricide broad spectrum of pyrethroids products that can be used in bee hives, gardens, greenhouses and disinfection of cuttings. In this regard, in the present study, the amount of residue of fluvalinate  in honey produced in Damavand region was measured with the aim of providing the health of consumers and preparing the ground for qualitative control of this product. The honey samples used in this study were prepared from six areas of Ayeneh Varzan, Aro, Havir, Mosha, Tar Lake and Damavand in June and September. The separation and detection of toxin were done by GC-MASS. Based on the results, the residue in June in all samples was more than the samples harvested in September. In this regard, the highest amount of residue was measured in June in Ayeneh Varzan (0.077 ppm) and the lowest was measured in September in Mosha (0.021 ppm).

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The guarantee of delayed payment price is one of the most important issues in the sales contract. The question is: “If the buyer does not pay the price on time, can the seller terminate the contract initially? Under the article 395 of civil code, the seller can require the buyer to pay the price or terminate the contract. But most of the writers, on the appearance of the article, have limited the seller's right to terminate the contract to the option of the delayed payment of price that appertains to cash price. They believe that in terms of price, the seller has the right to require the buyer to pay the price .This theory not only causes difficulties and injustices, but also is not coordinate by the laws of the developed countries and international trade. It cannot be justified by the civil law too. According to the writer of this article, contrary to the popular opinion, in the case of delay in payment, the seller in addition to the right of enforcement, can terminate the contract whether it is cash price or deferred.