Part 1：Determination of tobacco and tobacco products, and total plant alkaloids，Reference standard：YC/T468-2013

1、Theory：The tobacco sample was extracted with water, and the total plant alkaloids in the extract, measured as nicotine, reacted with p-aminobenzene sulfonic acid and cyanogen chloride, which is produced by an online reaction of potassium thiocyanate and sodium dichloroisocyanurate. The reaction products are determined with a colorimeter at 460 nm。

2、Reagent and material

2.1 Disodium hydrogen phosphate, purity>99.0%

2.2 Citric acid, purity>99.0%

2.3 p-aminobenzene sulfonic acid, purity>99.8%

2.4 Potassium thiocyanate, purity>99.5%

2.5 ferrous sulfate, purity>99.0%

2.6 Sodium carbonate, purity>99.8%

2.7 nicotine, purity>98%

2.8 polyethoxylaureth, add 250g of the solution to 1L of water, heat and stir until dissolved.

2.9 spectrophotometer

3.0 balancer 

Part2：Determination of tobacco and tobacco products, starch, reference standard: starch（YC/T216-2013）

1、Theory：Ultrasonic with 80% ethanol-saturated sodium chloride solution for 30min to remove the interfering substances in the tobacco sample, discard the extraction solution, and then extract with 40% perchloric acid ultrasonication for 10min, the starch underwent a chromogenic reaction with iodine under acidic conditions, and was determined at 570nm。

2、Reagent and material

2.1 Amylose, amylopectin, standard purity 99.8%

2.2 Sodium chloride

2.3 Absolute ethanol

2.4 Sodium hydroxide

2.5 perchloric acid solution, mass ratio 40%, pipette 300 ml of perchloric acid 4.5 and dissolve in 224 ml of water

2.6 perchloric acid solution, mass ratio 15%, pipette 52ml of perchloric acid 4.5, dissolved in 198ml of water

2.7 potassium iodide solution, weigh 5.0g potassium iodide and 0.5g iodine in a 400ml beaker, grind and mix with a glass rod, add a small amount of water to dissolve, and after complete dissolution, transfer to a 250ml brown volumetric flask, and set the volume to the scale with water.

2. 880% ethanol-saturated sodium chloride solution, weigh 64g of sodium chloride, dissolve in 200ml of water, add 800ml of absolute ethanol, dissolve, stand still, and filter after the solution is clear.

2.9 spectrophotometer

3.0 balancer

Part 3：Determination of tobacco and tobacco products, total nitrogen, reference standard: total nitrogen（YC/T161-2002）

Principle: Under the action of concentrated sulfuric acid and catalyst, organic nitrogen-containing substances are decomposed by strong thermal digestion, and the nitrogen in them is converted into ammonia, and under alkaline conditions, ammonia is oxidized to ammonium chloride by sodium hypochlorite, and then reacts with sodium salicylate to produce a dye, which is determined colorimetrically at 660nm. 

Part4：Tobacco and tobacco products 、total sugar（YC/T159-2019）,Reducing sugar（YC/T159-2019）

Principle：The samples were extracted with 5% acetic acid aqueous solution, and the sugars in the extract reacted with hydroxybenzoic acid hydrazide to produce yellow azo compounds in an alkaline medium at 85 degrees Celsius, and its maximum absorption wavelength of 410 nm was determined by colorimetric method.

Part5 ：Tobacco and tobacco products、chlorine（YC/T162-2011）

Principle：Chlorine in the sample was extracted with water, and the chlorine reacted with mercury thiocyanate to release thiocyanate, which then reacted with ferric iron to form a complex, and the reaction product was determined colorimetrically at 460 nm. 

Part 6：Spectrophotometer standard parts