Question: Interpret the results with respect to the relationshipvbetween reality

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Question: Interpret the results with respect to the relationshipvbetween reality and theory. (explain in detail please!!!!) Part A and B: Test kit for pesticides in vegetables-qualitative and quantitative analysis The vegetables and fruits reach the consumers throughout the world in a very short period o time order to protect the consumers from the pesticide residues left, rapid and reliable test a response to this issue, South China Agricultural University developed a rapid in 1995. Parts leaves and flower of Brassica parachinesis are provided here required to analysis all samples n both qualitative and and you are quantitative ways Part A.) Qualitative analysis 1. markets You will be provided with 5 detection cards, mark the card with your group no. and sampl 2. Cut the lower 4) e control 50-ve control fully in vegetable sample into small pieces (about 1 cm 5g and shake up the sample a bottle with 10mL pure select water 3. the film of pesticide detection card, dip the white disc into the water prepared in the last step) 4. Standing the card for at least 10 minute at room temperature. 5. Fold the card in half with your fingers for 3 minutes (so as to keep the reaction temperature at about 37 C, let the white disc and the red disc react during the process. 6. Determine the results according to the color change of the white disc. Positive results: no color change or just light blue of the white disc (no color change indicate a high pesticide residue, light blue indicate a relatively low pesticide residues) The detection limits of pesticide detection card to several commonly used pesticides are as follows Methamidophos. 1.7 Malathion: 20 Isocarbophos: 3.1 on 1.1 omethoate: 2.3 Monocrotophos. 2.5 Acephate: 3.5 Dichlorvos: 0.3 Dimethoate 1.3 Dipterex: 0.3 Carbofuran: 0.5 Carbaryl 2.5 Carbosulfan: 1.0 There are a lot of secondary metabolites in plants which could result in false positive. Also, high chlorophyll vegetables could give rise to pigment interference. It is recommended to soak entire vegetable leaves or adopt surface detection method when dealing with these vegetables Reaction rate slows down when the temperature below 37 C, the reaction time should be extended accordingly when adding wash solution onto white disc. It is comparable only when samples detection card and control detection card have the same reaction time. 3 minute would be the right time after folding the card, the blue color would become increasingly deeper after 3 minutes, and the color fade away after 24h Part B.) Quantitative analysis ophosphorus type pesticides could inhibit the activity of cholinesterase under certain conditions. If the samples contain organophosphorus, the amount can be detenmined through the calculation of inhibition rate, which has positive correlation with pesticide concentration. Reagents preparation 1. Phosphate buffer: Dissolve one pack of buffer powder with 500mL pure water, store at room temperature.

Explanation / Answer

Organophosphorus containing pesticides inhibit the cholinesterase activity. The amount of organophosphorus present can be determined by the rate of inhibition.

Part B is the quantitative analysis of the pesticide presence in the plant tissue

Part B table is created after performing the experiment of reaction of pesticide with the enzyme cholinesterase. The results in the part B indicate the percentage of the inhibition rate that was evaluated in the stem, leaf and flower from three samples of about 15 groups. If the percentage is found greater than or equal to 50%, then it means that pesticide is present in the sample that could inhibit the cholinesterase. If the percentage is less than 50%, it means that there is no pesticide in the sample that can inhibit the enzyme. Here, the three samples like stem, leaf and flower were considered. Stem, leaf and flower of three different samples are taken (A, B, and C).

The empty boxes in the flower samples of sample A, B and C indicates that the results were not shown or recorded in these groups.

Part A is the qualitative analysis of the presence of pesticide in the plant tissue

If the pesticide detection card has no change in its color, it means that the amount of pesticide is very high. If the color change is light blue it means that the pesticide content is very low. In the samples of Brassica parachinensis classified into 15 groups under three categories, 6 of the stem samples had pesticide detected on them. Eight of the leaf samples were detected to have pesticide on their surfaces. Three of the flower samples had pesticide on them. All the samples that were found to be having pesticides either incorporated into the tissue or staying on the surface would appear without any color change.

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