用科技论文语言改写以下内容：Leaf tissue was ground in liquid nitrogen and then transferred to a 50 ml centrifuge tube Ethanol 80 was added to the tube and the mixture was vortexed for 30 seconds The tube was then i

Leaf tissue was pulverized into fine powder using liquid nitrogen and subsequently transferred to a 50 ml centrifuge tube. An 80% ethanol solution was added to the tube, followed by 30 seconds of vigorous vortexing. The tube was then placed in a dark environment at a temperature of 4°C for a duration of 24 hours. The resulting extract was subjected to centrifugation at 5000 rpm for 10 minutes, and the supernatant was collected. The extract was then analyzed for its absorbance at 665 nm, 649 nm, and 470 nm using a spectrophotometer. The content of chlorophyll a, chlorophyll b, and carotenoids in the extract was determined by employing the equations outlined by Lichtenthaler and Wellburn (1983)