GB/T 3711-2008Method of determination for neutral oils and pyridine bases contents of phenol products (English PDF)

4.1 Xylene

AR.

4.2 Sodium hydroxide solution

27% solution.

4.3 hydrochloric acid solution

0.1mol/L standard solution, 0.5mol/L standard solution or 1mol/L standard solution.

4.4 phenolphthalein indicator

0.5g phenolphthalein dissolved in 100mL95% (volume fraction) ethanol.

4.5 bromophenol blue indicator

0.3% solution preparation method of dissolving 0.3g bromophenol blue in 100mL40% ethanol.

4.6 Buret

volume 25mL, 0.1mL with sub-scale.

4.7 Erlenmeyer flask

volume 500mL, graduated.

4.8 pipette

Volume 5mL.

4.9 cylinder

the volume of 100mL.

4.10

gas lamp.

4.11 distillation apparatus

the volume of 1000mL hard glass decanter, glass tube splash ball, bubble tube, a cooling tube, glass receptacle,

500mL conical flask with a volume scale composition, as shown in Figure 1 to 6.

Figure 1 apparatus for distillation assembly drawing

Millimeters

Figure 2 glass bulb splash

Millimeters

Figure 3 bubble tube

Millimeters

Figure 4 condenser

Millimeters

6.1 Determination of neutral oil

6.1.1

Prior to testing, the receiver and the Erlenmeyer flask strict cleaning lotion clean, the receiver section with lotion scale foam wash with distilled

Rinse.

6.1.2

In a clean sink, add distilled water to the mark 0.5mL ball at the mark, and then added with a pipette 3mL ~ 4mL

Xylene, xylene careful not to drop the ball on the wall, standing stand before installation instrument readings recorded.

6.1.3

accurately weighed sample evenly 100mL, (if the sample during the distillation of crude phenol foam easily affect distillation, sample volume can be reduced to

50mL; neutral oil or solid matter content greater than 1mL long time, sample volume reduced to 50mL) was poured into 1000mL distillation flask, and the amount of

Barrel sample stream as much as possible, with the same sodium hydroxide solution was added 170mL graduated cylinder, and at the same time shake the bottle, followed by the graduated cylinder add

100mL of distilled water (sample volume is 50mL when analyzed, add 85mL of sodium hydroxide solution, coupled with 185mL distilled water), full roll

Uniform, in order to prevent bumping, add a few slices of various porcelain pieces.

6.1.5

ensure bubble tube is not blocked, and then open the cooling water, cooling water condenser maintained continuously, heated to distill, distillation, distillation

Put a bottle of asbestos network, about the middle of the circular asbestos 50mm diameter. When the condensate liquid begins to flow, that is, open the lower part of the piston and receiver

Keeping close xylene liquid column height 4mL to gather 200mL distillate within about 30min ~ 40min distillation rate distillation distillate

The inner surface of the fluid flow along the receptacle, during the distillation (or melt condensation ago) does not allow steam to escape from the end of the condenser.

6.1.6

When the solids occurs when distilled liquid close 180mL, closed cooling water to melt the coagulated solids, solids to be full penetration, open

Cooling water, 200 mL of distillate was approaching, the heating was stopped, the condensate is dropped completely. The residue is hot pour, if the residue curing phenomenon, in

Bubble tube upper portion of hot water to melt slowly added, if the bottom caking, dilute sulfuric acid wash to soak.

6.1.7

xylene so receptacle located scale section, standing 15min, accurately read the volume of xylene.

6.1.8

The receiver of an aqueous solution of xylene and move all Erlenmeyer flask and distillate were combined and washed twice with distilled water 20mL

Di receiver, washing liquid incorporated into a conical flask, retain all distillate A, for determination of alkali content of pyridine.