Whatman offers a range of pH indicator and test papers to meet your specific needs. Made with traditional Whatman quality, these products combine ease-of-use with unsurpassed accuracy and consistency.
The convenience of using indicator papers for the rapid determination of pH values has led to many applications in laboratories and industry.
Features and benefits
- Instant pH readings
- Accurate for a wide range of routine pH testing
- Inexpensive
- Convenient and portable for field use
pH Indicators
Strips Type CF
Individual plastic support strips carry four different segments of dye-impregnated indicator papers. The resulting combination of color differences gives an extremely clear and accurate visual pH value. All the dyes are chemically bonded to the paper and cannot be leached into solution; problems associated with contamination of the sample and resultant anomalous readings are avoided.
Strips Type CS
Each test strip has a central segment of indicator dye and, printed alongside, 8 or more different color segments marked with corresponding pH values for matching purposes. The pH test value can be read off by direct comparison of the test strip color and the color bars. Ideal for colored solutions, when any changes in color of the paper stock are automatically cancelled out.
Dispensers Type TC
The strip has 3 separate indicator dye color bands. The combination of color change resulting from each test is compared with the color-coded comparison chart, printed on the dispenser, giving improved speed and accuracy in reading.
Dispensers Type SR
A full range and some narrow ranges in this popular pH indicator dispenser.
Indicator Books
The book format is particularly suitable for educational and industrial use. In schools they are economical because the amount of paper per student can be carefully controlled.
Acid-Alkali Test Papers
Litmus Blue and Litmus Red
These easy-to-use test papers facilitate a general test for acid or alkaline reaction. The change occurs around pH 5 to 8. They are particularly recommended for educational use.
Congo Red
This test paper changes color from blue to red in the range pH 3 to 5 for the determination of neutralization point in strong acid/weak alkali reactions.
Phenolpthalein
This white paper changes to pink at pH 8.3 and becomes red at pH 10. It is useful for the determination of the neutralization point in weak acid/strong alkali reactions.
Specialized Test Papers
Lead Acetate Test Paper
Used for detecting hydrogen sulfide, this rapid qualitative test paper when wetted with distilled water can detect as little as 5 ppm of H2S in the atmosphere or in a gas stream. Hydrogen peroxide can be detected with this paper by preblackening the paper in H2S. Concentrations as low as 4 ppm can be detected.
Potassium Iodide Test Paper
Used for detecting chlorine and other oxidizing agents. In acid solution, oxidizing agents react with the iodide in the test paper to liberate iodine. The paper will turn blue in the presence of an oxidizing agent (e.g., CI2, Br2, H2O2, HNO2 etc.).
Universal Indicator Papers
Universal indicator papers have been impregnated with a mixture of several indicators. On contact with the sample solution they assume a particular color. A check against the color comparison table supplied allows the pH to be determined.