Specific operation steps:

(1) Weigh 100mg hair sample and place it in a 15mL glass tube. Add 10mL isopropyl alcohol. Place the tube on a multi-purpose shaker at room temperature and wash it for 3min (100 times/min) for 2 times. Dry the washed sample in a constant temperature drying box at 37℃ for 8h.
(2) After drying, put the sample into a 80mL small beaker and crush it with surgical scissors. Then put it into a 25mL stainless steel grinding jar (with a 15mm stainless steel grinding ball inside), tighten the jar and put it into liquid nitrogen to freeze until the liquid nitrogen stops boiling. Grind the jar in a frozen mixed ball mill MM400 for 2.5min (26Hz).
(3) Weigh about 50mg hair powder and place it in a 10mL centrifuge tube, and add 8mL methanol. Place the centrifuge tube on an oscillator at room temperature and shake it for 24h (230 times/min).
(4) Centrifuge the centrifuge tube for 5min (12000g), and take 1mL supernatant into a 1.5mL centrifuge tube.
(5) Take 0.8mL supernatant from the 1.5mL centrifuge tube into a 2mL centrifuge tube, dry it with nitrogen flow at room temperature.
(6) After drying, add 0.45mL PBS (phosphate buffer solution: NaCl 8g, KCl 0.2g, Na2HPO4 1.44g, KH2PO4 0.24g, adjust the volume to 1L with deionized water, adjust the pH to 7.4) to reconstruct the sample. Mix well after shaking, store it in a −20℃ refrigerator until the detection day.

Chinese:

具体操作步骤：
（1）称取100mg毛发样品置于15 mL玻璃试管中，加入10 mL异丙醇。在室温下将该试管放于调速多用振荡器上洗涤3 min（频率100 次/min），共洗涤2 次；洗涤后的样品置于电热恒温干燥箱内，37℃干燥8h。
（2）干燥后将样品放入80 mL小烧杯内，用手术剪剪碎。之后放入25 mL不锈钢研磨罐内（内有15mm不锈钢研磨球一个），拧紧后将罐放入液氮内冷冻至液氮停止沸腾。将研磨罐装入冷冻混合型球磨仪MM400，研磨2.5 min（频率26 Hz）。
（3）称取约50 mg毛发粉末，置于10 mL离心管内，并加入8 mL甲醇。室温下，将离心管置于振荡器，振荡24 h（频率230 次/min）。
（4）将离心管离心5min（离心力12 000 g,），取1 mL上清液移入1.5 mL离心管内。
（5）在1.5 mL离心管内取0.8 mL上清液放入2mL离心管，室温用氮气流进行干燥 
（6）干燥后加入0.45mL PBS (磷酸缓冲液：NaCl 8 g, KCl 0.2 g, Na2 HPO4 1.44 g, KH2PO4 0.24 g，加去离子水定容至1 L，将pH值调整到7.4)对样品进行重构。振荡混匀后，放入−20℃冰箱内储存至检测日。