Preparation of cleaning solution
Five types of cleaning solutions were prepared as follows:
Soda-salt solution: For the soda-salt solution (5%), 5 g of edible
soda and 5 g of salt was added into 1 L of water. Then, the solution
was stirred until completely dissolved.
Tamarind juice solution: 50 g of tamarind without its seed was
weighted. Then, 1 L of water was added to tamarind and it was
soaked for 15 min.
Flour solution: For the flour solution, 50 g of flour was weighted.
Then, the flour was poured into 1 L of hot water; the solution was
stirred until completely dissolved and filtered from the suspension.
Vinegar solution: For the vinegar solution, 100 ml of vinegar was
measured. Then, 900 ml of water was added into vinegar, the
solution was stirred lightly to dissolve the solutions. If there was
residue present in the solutions, the solution was filtered and
supernatant was collected.
Preparation of simulated chlorpyrifos pollution in cauliflower
Preparation of chlopyrifos mixture: 2.0 L of water was added into
the 0.95 ml of chlorpyrifos. After water was added, the mixture was
stirred until dissolved.
Preparation of chlorpyrifos pollution in cauliflower: A cauliflower
of 1000 g was bought from the supermarket and washed with tap
water and dried with absorbent paper. Then, the cauliflower was
soaked in chlorpyrifos mixture for 10 min and stored at room
temperature in a dark room for 24 h