Titration of Alkaline Etching Solutions for Activity
A test kit is available for this titration procedure (see below) or supplies can be ordered individually
Complete Test Kit Part Number: OKT9601-79 (or 45218519)
| Solution-Item | Item | Amount | Part Number | BASF Number |
| Gardotest Indicator 2 | Phenolphthalein | 30 mL | OKT-2246-G | 50560520 |
| Gardotest Indicator 98 | Eriochrome Black T / Sodium Chloride | 30 g | OKT-9257-G | 50560640 |
| Gardotest Indicator 193 | Methyl Red Indicator | 60 mL | OKT-2292-H | 50560527 |
| Gardotest Solution 90 | 0.10 M Versene (Disodium EDTA) | 250 mL | OKT-9656-K | 50560654 |
| Gardotest Solution 91 | 0.10 M Zinc Sulfate | 250 mL | OKT-9657-K | 50560656 |
| Gardotest Solution 90 | 0.10 M Disodium EDTA | 250 mL | OKT-9656-K | 50560654 |
| Gardotest Solution 99 | Buffer (Ammonium Chloride/Ammonium Hydroxide) | 100 mL | OKT-4255-J | 50560562 |
| Gardotest Solution 116 | 10% Sulfuric Acid | 250 mL | OKT-6542-K | 50560625 |
| Gardotest Solution 202 | 0.50 N Sulfuric Acid | 250 mL | OKT-6090-K | 50560582 |
| Gardotest Solution 215 | 20% Barium Chloride | 250 mL | OKT-9655-K | 50560653 |
| Glass Bottle | 120 mL | 2 | OKT-9688 | 45218454 |
| Direct Reading Pipette, Glass | 0.0 to 5.0 mL | 7 | OKT-9685 | 45218454 |
Refer to the product specific technical information sheet for the appropriate sample size and multiplying factor F or ask your technical sales representative if not listed here.
Procedure
Part I: Total Titration (Active Etchant plus Sodium Aluminate Contamination):
|
1. Fill the 120 mL sample bottle about half full with tap water. Next, add 5-6 drops of Gardotest Indicator 2. 2. Measure precisely 5 mL sample using one of the droppers and add it to the mixture prepared in step 1. The color will be red. 3. Fill another 5 mL dropper precisely to the zero mark with Gardotest Solution 215 and add it to the mixture prepared in step 2. Swirl to mix. Allow to stand at least 5 minutes |
4. Fill the 5 mL glass direct reading pipette precisely to the zero mark with Gardotest Solution 202. Add this to the mixture in the sample bottle a few drops at a time, swirling between additions, until the color changes from red to white and holds for at least 2 minutes. Record the number of mL used. Call this Titration T. CALCULATION T x F = vol % (g/L or oz/gal) active etchant plus sodium aluminate contamination = A |
Part II: Aluminum Contamination up to 27 g/L (3.6 oz/gal):
|
1. Fill the 120 mL sample bottle about half full with tap water. Using the 1 mL dropper measure out precisely 1.0 mL of the etchant solution to be tested. 2. Add this to the water in the sample bottle. Swirl to mix. 3. Add 2 drops of Gardotest Indicator 193 and swirl to mix. Next, add Gardotest Solution 116, a few drops at a time with swirling between additions, until the yellow color changes to a clear, light red. |
5. Using the 5 mL dropper, add precisely 10.0 mL of Gardotest Solution 90 to the mixture in the bottle. Swirl to mix. Next, add 3.0 mL of Gardotest Solution 99 and swirl to mix. The color should be a clear, very light yellow. Finally, add 1 mini-spoonful of Gardotest Indicator 98 to the contents of the bottle and mix well. The color should change to a distinct blue. 6. Fill the 5 mL calibrated pipette precisely to the zero mark with Gardotest Solution 91 and add this, a few drops at a time with swirling between additions, until the color changes from blue to wine red. Record the number of mL used. Call this Titration T. This completes the analysis. |
CALCULATION
(10 – T) x 4.0 = aluminum contamination (g/L NaOH bound as sodium aluminate) = B
(10 – T) x 0.53 = aluminum contamination (oz/gal NaOH bound as sodium aluminate) = B
FINAL CALCULATION
A – B = g/L or oz/gal active etchant in solution. (NaOH)
Note: Part II may be calculated to give aluminum expressed in other ways:
(10 – T) x 2.7 = g/L of aluminum
(10 – T) x 0.36 = oz/gal of aluminum
(10 – T) x 0.82 = %NaAlO2
(10 – T) x 0.40 = %NaOH
NOTE:
1. Using the procedure as outlined in part II above, aluminum content of solutions up to 27.0 g/L or 3.6 oz/gal can be measured.
2. If the solution contains more than 27.0 g/L or 3.6 oz/gal of aluminum, the color of the solution will turn red instead of blue after adding Gardotest Indicator 98 in step 3. If this happens, empty the sample bottle, rinse thoroughly with tap water and start again. Proceed to step 3 and then, using the 5 mL dropper four times, add precisely 20 mL of Gardotest Solution 90. Complete the titration as directed.
(20 – T) x 2.7 = g/l of aluminum
(20 – T) x 0.36 = oz/gal of aluminum
(20 – T) x 2700 = parts per million (ppm) aluminum
3. Depending on the amount of aluminum in solution it may be necessary to add 30 ml or even 40 mL of Gardotest Solution 90. Adjust the calculation accordingly:
(30 – T) x 2.7 = g/L of aluminum
(30 – T) x 0.36 = oz/gal of aluminum
or
(40 – T) x 2.7 = g/L of aluminum
4. (40 – T) x 0.36 = oz/gal of aluminum
SUGGESTION OF OTHER PRODUCTS YOUR COMPANY MAY USE
• CLEANERS
• ETCHANTS
• DEOXIDIZERS
• RUST PREVENTIVES
• METALWORKING FLUIDS (coolants and lubricants)
• WASTE WATER TREATMENT CHEMICALS
• FLOOR CLEANERS AND MAINTENANCE PRODUCTS
• PROCESS EQUIPMENT/CONTROL SYSTEMS
DISTRIBUTED BY NALTIC INDUSTRIALS AN AUTHORIZED DISTRIBUTOR FOR THE USA
Chemetall US, Inc. (“Chemetall”) warrants that products described within its official technical papers will conform with its published specifications. The products supplied by Chemetall and information related to them are intended for use by buyers having necessary industrial skill and knowledge. Buyers should undertake sufficient verification and testing to determine the suitability of the Chemetall materials for their own purpose. Since buyer’s conditions of use of products are beyond Chemetall’s control, Chemetall does not warrant any recommendations and information for the use of such products.
CHEMETALL DISCLAIMS ALL OTHER WARRANTIES INCLUDING THE IMPLIED WARRANTY OF MERCHANTABILITY AND FITNESS FOR ANY PARTICULAR PURPOSE IN CONNECTION WITH THE USE OF ITS PRODUCTS.
Please contact us directly for a complete and official Chemetall Technical Data Sheet and/or MSDS in PDF.