Ethylene oxide content analyzer

FJ-21Type ethylene oxide content analyzer

Ethylene oxide content analyzer

1、 Introduction

FJ-21The type of ethylene oxide content analyzer is used according toGB/T7385-94Determination of Ethylene Oxide Content in Surfactant Ethylene Oxide Adducts The Iodine Content Method stipulates the design and production. This device is suitable for determining the content of ethylene oxide groups in the adducts of ethylene oxide with saturated primary fatty alcohols, oil alcohols, saturated fatty acids, linear and branched alkylphenols, and other substances. Determination of the content of ethylene oxide groups in polyoxyethylene surfactants by iodometric method, applicable to saturated primary fatty alcohols, oleanols, and saturated fatty acids,Polyethoxylated derivatives of linear and branched alkylphenols are also applicable if unreacted alcohols, fatty acids, or alkylphenols are present in the derivatives.

2、 Principle

Ethylene oxide group is hydrolyzed by newly generated iodate,The released iodine is titrated with Liu sodium sulfate standard solution,Thus, calculate the mass fraction of ethylene oxide groups.

The basic reaction equation is as follows:

RO-(CH,CH,0)-H+2HI-nICH-CH:I+ROH+nH,O

3、 Measurement

1.Invert the round bottom flask onto the weighing rod containing the sample,Then stand the flask upright,Slide into the flask,One end with a conical surface is located at the bottom of the beaker.

2.plus3gIodide is added to the flask. Connect the intake pipe and condenser to the flask,Use a small amount of phosphoric acid as a lubricant for the ground glass joint, place phosphoric acid in the liquid sealed tank, and introduce nitrogen or carbon dioxide into the flask,The flow is slightly larger than0.5mL/sAt least through20min.

Without interrupting the airflow,Transfer the entire set of flasks, condensers, inlet pipes, etc. to the oil bath,Add personnel from the upper opening of the condenser5mLPhosphoric acid is added to the flask,Then connect the spherical absorber to the other end of the condenser,And add7mL~10mL,Iodide dissolves into a spherical absorber.

3.The temperature of the oil bath is controlled at165 ℃ Shi1℃,Simultaneously reduce the gas flow rate to0.1 mL/s ~0.5 mL/sThe reaction proceeds30 min,In the back20 minRequire the temperature of the oil bath not to exceed the specified value, and remove the flask from the oil bath,Without interrupting the airflow,Cool down to80Stop ventilation below ℃,Quickly rotate the interface shaft of the spherical absorber system,Allow the liquid in the spherical absorber to enter the flask through the condenser. Rotate the spherical absorber back to its original position,put in7mL~10mLPotassium phosphide solution. As mentioned before,Transfer to the condenser interface and intake pipe interface, and collect the washing solution in the flask.

4.Move the liquid inside the flask to250mLCone shaped bottle,Wash the flask with water and a few milliliters of iodine solution. If there are undissolved residues,Can you add a few milliliters of methanol to dissolve it,And pour it into a conical flask. Titration with Liu sodium sulfate standard solution,When the color above iodine is about to disappear,Add starch solution,Continue titration until the blue color disappears as the endpoint.

4、 Air Self Test

At the same time as measuring the sample,Using the same reagents,Follow the same measurement steps,Perform parallel operations without adding samples.

Ethylene oxide content analyzer