润滑油中酸值检测方案(自动电位滴定)

KeM Application Note No.TIA-06312Petroleum A c i d n u m b e r o f l u b r i c a n t Non-aqueousproducts titration 1. Abstract The Acid number of petroleum products and lubricants can be determined by thepotentiometric titration method with 0.1mol/L Potassium hydroxide·2-propanolsolution accordingto“JISsK2501 Petroleum products； andlubricants-determination of neutralization number”，“ASTM D664 Standard Test Method forAcid Number of Petroleum Products by Potentiometric Titration”and“ISO 6619Petroleumproductsand lubricants-Neutralizationnumber- Potentiometrictitration method”and the like. The endpoint is the inflection point in the titrationcurve. The Acid number of petroleum products and lubricants is calculated from thevolume titrated of Potassium hydroxide·2-propanol solution. The samplesshould be previously dissolved in the mixture of solvents — usually comprised ofToluene， 2-propanol and a smalll amount of distilledwater. The acidiccomponents of petroleum products and lubricants which are dissolved in thismixed solvent are： Organic acids， Inorganic acids， Ester， Phenol compounds，Lactone， Resin， Heavy metal salts， Ammonium salts or other weak acidiccompounds and Polybasic acid salts and the like. 2. Reference 1) JIS K2501 Petroleum products and lubricants - determination of neutralizationnumber 2) ASTM D664 Standard Test Method for Acid Number of Petroleum Products byPotentiometric Titration 3) ISO 6619 Petroleum productsand lubricants；- Neutralization number-Potentiometric titration method 3.Tips for measurement 1) Immerse the electrode in distilled water for ca a few minutes to one hour aftereach measurement in order to restore the sensitivity of the electrode(Depolarization). 2) Standardize Potassium hydroxide·2-propanol solution frequently enough todetect concentration changes of 0.0005mol/L or less. ( TIA-06312 1/4 ) 上海市漕溪路222号航天大厦北楼902室网址： http：//kem. instrument. com. cn 4.l. Equipment Main unit ： Automatic potentiometric titrator AT-510 Detector ： Standard preamplifier STD-510Combination glass electrode C-172+ Cable #429-0012 5. Reagent Titration solution ： 0.1mol/L Potassium hydroxide·2-propanol solution Solvent ： mixture of 500mL of Toluene， 5mL of water， and 495mL of2-propanol. 6. Analysis Procedure 1) Place ca. 0.2g of sample in 200mL beaker. 2) Add 100mL of solvent. 3) T1itrate with 0.1mol/L Potassium hydroxide·2-propanol solution to determine thetotal acid number of lubricant. 7. Calculation Total acid number (mg/g)：(EP1-BL1)xTFxC1xK1/SIZE EP11： volume (mL) BL1 ： blank (mL)=0 ： titrant factor=0.9999 ： concentration conversion coefficient=5.611 (1mL of 0.1mol/L KOH-(CH3)2CHOH corresponds to 5.611mg of KOH) K1 ： unit conversion coefficient=1 SIZE ： sample size (g) 上海市漕溪路222号航天大厦北楼902室网址： http：//kem.instrument.com.cn 8. Example of Measurement -Ambient condition- Room temperature： 22.5°℃ Humidity： 47% Weather： Cloudy 上海市漕溪路222号航天大厦北楼902室网址： http：//kem. instrument. com.cn -Results- Run Size(g) Vol.(mL) Total acid number(mg/g) 1 23 0.21760.19360.2086 4.35763.8418 4.1693 112.35111.33 112.14 Statistics MeanSD RSD 111.94 mg/g0.5371 mg/g0.4798% 【AT-610】【AT-510】 【AT-500N-1】 Awarded Supreme Technology fromKyoto City · Compact and cost performancemodel ·Low cost and high performance · Easy view with back light LCD · Easy key entry by touch panel oflarge color LCD (8-inch wide) ·PC card expands data memory forconvenience and versatility. · GLP/GMP conformed model · Simultaneous titration in parallel · Both potentiometric and KarlFischer moisture titration(coulometric·volumetric) can beperformed at a time. K-M KYOTO ELECTRONICSMANUFACTURING CO.，LTD. Overseas Division： 8-3，Niban-cho，Chiyoda-ku，TOKYO 102-0084 JAPAN FAX：+81-3-3237-0537， Phone：+81-3-3239-7333 E-mail： export@kem.co.jp URL：http：//www.kyoto-kem.com Factory： 56-2 Ninodan-cho，Shinden Kisshoin，Minami-ku，KYOTO601-8317，JAPAN FAX：+81-75-691-9961， Phone： +81-75-691-4122 E-mail： tech-english@kem.co.jp TIA-06312 4/4 京都电子工业株式会社-可睦电子(上海)商贸有限公司上海市漕溪路222号航天大厦北楼902室电话：021-54488867 电邮： kemu-kem@163.com网址： http：//kem. instrument.com.cn 京都电子工业株式会社-可睦电子(上海)商贸有限公司电话： 电邮： kemu-kem@com