Disposable Syringes - Appendix 1
Preparation of ethylene oxide residual solution
0.1mol/L hydrochloric acid: dilute 9ml hydrochloric acid to 1000ml.
0.5% periodate solution: weigh 0.5g of periodate and dilute to 100ml.
Sodium thiosulfate solution: weigh 1g of sodium thiosulfate and dilute to 100ml.
10% sodium sulfite solution: weigh 10. 0g anhydrous sodium sulfite, dissolve it and dilute it to 100ml.
Magenta sulfurous acid test solution: weigh 0.1g of basic fuchsin and add 120ml of hot water to dissolve it. After cooling, add 20ml of 10% sodium sulfite solution and 2ml of hydrochloric acid in the dark. The test solution should be colorless. If it is found to be reddish, it should be re prepared.
Ethylene glycol standard stock solution: take an external dry and clean 50ml volumetric flask, add about 30ml of water, weigh it accurately, take 0.5ml ethylene glycol, quickly add it into the bottle, shake it up, weigh it, the difference between the two weights is the weight contained in the solution, add water to the scale, mix it up, and calculate its concentration according to the following formula:
C＝W/50 × one thousand
C: Glycol standard stock solution concentration g/l;
W: Weight of ethylene glycol in solution g
Ethylene glycol standard solution: accurately take 1.0ml of standard stock solution, and dilute to 1000ml with water.
Preparation of easily oxidized reagent:
a. Dilute sulfuric acid (20%): Take H2SO4128ml, slowly inject 500mL, and dilute to 1000mL after cooling.
b. Starch indicator: take 0.5g of soluble starch, dissolve it in 100ml of water, heat and boil it, and then cool it for standby (it shall be newly prepared when it is used temporarily)
c. Potassium permanganate solution: take 3.3gKMnO4, add 1050ml of water, boil for 15min, add water to 1050ml, leave it to stand for more than two days after sealing, filter it with microporous glass funnel, shake it up, and calibrate its concentration.
Calibration: Take 0.25g of reference sodium oxalate dried to constant weight at 1050C, weigh it accurately, add 100ml of sulfuric acid solution (8+92) and stir to dissolve it. Quickly add 25ml of KMnO4 standard solution to be calibrated into the solution from the buret. After fading, heat it to 650C and continue titrating until the solution turns red and remains unchanged for 30s. At the end point of titration, the solution temperature shall not be lower than 550C, and the blank test shall be conducted at the same time. Every 6.7mg of sodium oxalate is equivalent to 1ml of 0.02mol/L KMnO4 standard solution. The actual concentration of this solution is calculated according to the consumption of this solution and the amount of sodium oxalate taken.
d. C (KMnO4)=0.002 mol/L: Take 0.02 mol/L KMnO4 and add water to dilute it 10 times before use
e. Sodium thiosulfate (0.1 mol/L): weigh 26g Na2S2O3.5H2O or 16g anhydrous Na2S2O3, add 0.2g anhydrous sodium carbonate, dissolve it in 1000ml water, slowly boil it for 10min, cool it, add water to 1000ml, filter it after two weeks, and calibrate its concentration.
Calibration: weigh 0.18g of reference potassium dichromate dried at 1200C to constant weight. Weigh accurately. Put it in an iodine measuring flask, dissolve it in 25ml of water, add 2g of potassium iodide and 20ml of dilute sulfuric acid (20%), shake well, place it in a dark place for 10min, add 150ml of water, titrate it with the prepared Na2S2O3 solution [c (Na2S2O3) ＝ 0.1 mol/L], add 2ml of starch indicator solution (10g/L) at the end point, continue titrating until the solution changes from blue to bright green, and conduct blank test at the same time. Every 1ml of Na2S2O3 (0.1 mol/L) is equivalent to 4.9031mg of potassium dichromate. The concentration of this solution is calculated according to the consumption of this solution and the amount of potassium dichromate taken.
f. C (Na2S2O3) ＝ 0.01 mol/L: dilute 0.1 mol/L Na2S2O3 with newly boiled and cooled water before stand by 10 times.
Post time: Oct-04-2022
