ASTM D2982 Test Methods for Detecting Glycol-Base Antifreeze in Used Lubricating Oils
PROCEDURE B - USING SHELF REAGENTS
14. Apparatus
14.1 Test Bottle - A 250-mL stoppered, graduated cylinder, or a 250-mL jar, approximately 57 mm in outside diameter, 127 mm tall, marked at 50-, 100-, and 175-mL volume levels.
15. Reagents and Materials
15.1 For purity and quality of reagents, see 7.1
15.2 Calcium chloride (CaCl2). (Warning - see Note 10.)
NOTE 10 - Warning: Toxic. Hazardous.
15.3 Methanol (CH3OH). (Warning - See Note 11.)
NOTE 11 - Warning: Toxic. Flammable.
15.4 Hydrochloric acid, concentrated (relative density 1.19).
15.5 Potassium Iodate (KIO4), powder. (Warning - See Note 10.)
15.6 Fuschin (Rosaniline Hydrochloride). (Warning - See Note 10.)
15.7 Pararosaniline Hydrochloride. (Warning - See Note 10.)
15.8 Sodium Bisulfite (NaHSO3). (Warning - See Note 10.)
15.9 Acid-Salt Solution Solvent - Using a graduated cylinder, add 100 mL of hydrochloric acid to 500 mL of water. When this has cooled down below 25°C (room temperature or lower), add 400 mL of methanol using a graduated cylinder; mix thoroughly.
NOTE 12 - Warning: Mixing hydrochloric acid with water generates heat. Always add the acid to the water and add it slowly. Never add the water to the acid.
15.10 Acid-Salt Solution - Dissolve 10 +/- 0.1 g of calcium chloride in the solvent prepared in 15.9.
15.11 Schiff's Reagent Solvent - Using graduated cylinders add 20 mL of concentrated hydrochloric acid (relative density 1.19) to 800 mL of water (Warning - See Note 12.) Mix thoroughly.
15.12 Schiff's Reagent - Into the solvent prepared in 15.11, dissolve 1.0 +/- 0.1 g of basic fuschin or pararosantiline or a mixture of both and 18 +/- 0.1 g of sodium bisulfite (NaHSO3) and dilute the solution to 1000 mL. Allow the solution to stand for a few hours or overnight before using. Store in an amber bottle away from direct sunlight.
15.13 Toluene. (Warning - Toxic. Flammable.) Naphtha (Warning - Toxic. Flammable) is a suitable alternative. See 16.3.
16. Procedure
16.1 Bring sample and reagents to a temperature of at least 21°C and preferably 27°C.
16.2 Fill the test jar with acid-salt solution to the 50-mL mark. Add 0.20 +/- 0.01 g of potassium periodate and dissolve by swirling the jar.
16.3 Shake the sample well (Section 8) and pour it into the jar to the 100-mL mark. Close the jar with the screw cap and shake the contents vigorously for about 30 s. Allow to stand for several minutes until the water and oil layers have separated. If the oil and water layers have not separated within 5 min, add 50 mL of naphtha or other appropriate glycol-free solvent immiscible with water and shake. This will reduce the viscosity of the oil and standing another 5 min or less should allow the layers to separate.
16.4 Add Schiff's reagent, filling the jar to the 125- or 175-mL mark if solvent was added, swirl to disperse the reagent, and allow the mixture to stand undisturbed.
16.5 Observe the color of the water layer.
17. Observations and Interpretations
17.1 Disregard any color appearing after the test has stood for 10 min. (16.4).
17.2 When a definite pink, red purple, or violet color appears at the oil-water interface within 10 min. of standing, perform a blank test on the same new, unused oil or, preferably, on the same used oil which is known to contain no antifreeze.
17.3 When the color at the oil-water interface is a definite purple or violet color and the blank (17.2) does not give the same color, regard the color as a positive test.
NOTE 13 - When there are several used oil samples to be tested consecutively and all are from the same new oil, only one blank test need be performed.
17.4 When a red or definite pink color appears at the oil-water interface, antifreeze may or may not be present. It depends on the intensity of the color relative to the blank.
17.5 When sugar or sugar-containing materials are suspected to be present or when the steps outlined in 17.3 and 17.4 cannot provide a definite answer, perform a water test as outlined in Test Method D95 using 20 mL of the test sample and 80 mL of toluene. Take the water (glycol) - toluene extract from the condenser trap and proceed as outlined in 16.3 and 16.4. The appearance of a purple or violet color within 10 min. indicates the presence of antifreeze in the original oil sample.
