The portable pesticide residue fastness tester is a specially designed instrument according to the national standard method GB/T5009.199-2003) speed measurement card method (paper sheet method). It is mainly used for the rapid detection of organophosphorus and carbamate pesticides in fruits, vegetables, tea, grain, water and soil. It is particularly suitable for the rapid detection of agricultural product quality inspection stations, production bases of fruits and vegetables and field farmland inspection before picking, and farm products. On-site inspection of the wholesale sales market, pre-processing safety inspection of restaurants, canteens, and family fruits and vegetables. Baby Octopus Baby Octopus ZHEJIANG EVERNEW SEAFOOD CO.,LTD , https://www.evernewseafood.com
Detection principle:
The detection principle of the instrument is the use of a cholinesterase (Card 2) in a rapid test card to catalyze the hydrolysis of indophenol acetate (Card 1) to acetic acid and indophenol, due to organophosphorus and carbamate pesticides against cholinesterase The activity of the enzyme has a strong inhibitory effect. Therefore, depending on the difference in coloration, it is possible to judge whether the sample contains organophosphorus or carbamate pesticide residues. 12
Instructions:
(1) Turn on the instrument Press and hold the “ON/OFF†button on the panel for about 2 seconds to turn on the instrument (press the secondary button again to turn the instrument off): Press the [MODE] button to switch to “TEMPERATURE†when the temperature reaches 40°C The instrument emits a tone and the warm-up is complete and the test can begin.
(2) Loading the tear test card to tear off the upper cover film folded, then insert the pressure on each channel under the heating plate (note that the end of the card 1 is on the top, the end of the card 2 is below), check the test card placement If the position is correct, the dashed line in the middle of the quick test card should be aligned with the bead. Do not skew.
(3) Select a representative sample of vegetable or melon skin, wipe the surface mud, cut into pieces of about one square centimeter, take 5 grams into a bottle with lid, and add 10 ml of purified water or buffer solution to shake 50 times (there are Conditional support can be equipped with ultrasonic cleaner stirring), standing for more than 2 minutes, each batch is best to do 9 samples, while doing a blank control of pure water or buffer, after each cut a sample, the knife can be washed before Place another sample to avoid contamination. Pipette 80 μl of the sample solution onto the white tablets. If the test is carried out at the sampling site or under rough conditions, directly drop 2-3 drops of eluent on the tip of the vegetables to be tested, and gently rub the tips of the other leaves at the drops to make the vegetable surface. The residual pesticide is fully dissolved into the lotion. Then drop a drop on (card 2).
(4) Test Press the <Start> key and the reaction starts counting down for 10 minutes (the "Reaction" indicator is on). When you hear the instrument beeps with a rapid beep, close the lid and start the color countdown for 3 minutes ("Color") The indicator is on): When the instrument sounds a gentle buzzer, open the upper cover of the instrument to determine the result. The results were compared with the blank control card. If (card 2) is not discolored or slightly yellowish is a positive result, no yellow is a strong positive result, indicating that the pesticide residue is high, and the yellow color is a weak positive result, indicating the amount of pesticide residues The machine is relatively low. (Card 2) becomes orange or the same as the blank control card and is a negative result. Additional notes This method is a biochemical reaction and should avoid as much as possible the effects of physical and chemical factors on enzyme activity. The optimum pH for the reaction is about pH 7.5. When the sample is acid or partially alkaline, it should be leached with phosphate buffer. During the reaction, the surface of the tablets should be kept moist. It is best to apply a uniform sample after each batch of samples has been processed to avoid excessive evaporation. Onion, garlic, radish, celery, white peony, mushrooms, and tomato sap contain plant secondary biomass that has an effect on enzyme activity and is prone to false positives. When processing such samples, it is not advisable to cut them and the extraction time should not be too long, so as to avoid excessive release of the juice and affect the test results. If necessary, the whole plant (body) vegetable extraction method can be used for the determination. The pesticide rapid test card is valid for one year under normal temperature conditions. It should be stored in a cool, dry and dark place at the time of storage. It is best for those who have conditions to put in a refrigerator at 4°C. After the pesticide speed test card is opened, it is best to use it within three days. If it cannot be used once, it can be stored in the desiccator. Rapid test card for pesticides Rapid detection card for pesticide residues in fruits and vegetables is an enzyme test paper made of cholinesterase and chromogenic reagent highly sensitive to pesticides. It can quickly detect the large amounts of organic phosphorus and carbamate in vegetables. Residues of insecticides with high toxicities, sensitive enzymes to methamidophos, strong anti-interference, easy operation, no preparation of reagents, no special technical training, and no need to use any equipment alone. It can also be used in conjunction with rapid pesticide detectors to improve detection efficiency. The product is easy to store and easy to carry. It is the best method for on-site testing.