1、 FORD LABORATORY TEST METHOD AK 103-01 Date Action Revisions 2001 01 22 Revised Editorial no technical change A. Cockman 2000 03 22 Revised Editorial no technical change A. Cockman 1992 10 16 Printed copies are uncontrolled Page 1 of 2 Copyright 2001, Ford Global Technologies, Inc. DETERMINATION OF
2、PERCENT NITRITE IN CLEANERS Application This method is used to determine the percent nitrites present in alkaline cleaner solutions and applies to those materials which do not contain amines, nitrates or ammonium compounds. Solutions Required 0.1 N and/or 0.5 N NaOH 0.1 N and/or 0.5 N HC1 Methyl Red
3、 Indicator Powdered C.P. Zinc Crystalline Ferrous Sulfate 30 % NaOH Solution Apparatus Required Distillation Apparatus Volumetric Flask - 1 liter Analytical Balance - sensitive to .1 mg Erlenmeyer Flask - C.A.P. Conditioning and Test Conditions All test values indicated herein are based on material
4、conditioned in a controlled atmosphere of 23 +/- 2 C and 50 +/- 5 % relative humidity for not less than 24 h prior to testing and tested under the same conditions unless otherwise specified. FORD LABORATORY TEST METHOD AK 103-01 Page 2 of 2 Copyright 2001, Ford Global Technologies, Inc. Procedure 1.
5、 Weigh 10.0 g of sample into a 1 liter volumetric flask. 2. Dissolve in distilled water and dilute to 1 liter. Note: It may be necessary to add defoaming agents (kerosene or silicone) to suppress foam. 3. Aliquot 50 mL of this 1 % solution into a 500 mL Kjeldahl distillation flask. 4. Dilute to 250
6、mL with distilled water. 5. Add 5.0 g powdered zinc. 6. Add 2.0 g of powdered ferrous sulfate. 7. Add 50 mL of a 30 % NaOH solution. 8. Distill the converted nitrite into an Erlenmeyer flask containing exactly 50 mL of either 0.1 N or 0.5 N HC1 to which 5 drops of methyl red indicator has been added
7、. 9. Collect at least half of the volume present in the Kjeldahl distillation flask, usually 45 minutes time for the completion of the distillation. 10. Back titrate the excess HC1 with NaOH of the same normality. 11. Calculate NaNO2 as follows: % NaNO2 = mL HCl Used x Normality x .069 x 100 Weight of Sample Chemicals, materials, parts, and equipment referenced in this document must be used and handled properly. Each party is responsible for determining proper use and handling in its facilities.
