Residue Testing with pH Strips
Q. Can I use pH paper to confirm cleaning and rinsing of labware to comply with lab accreditation requirements?
A. If you are going to use pH strips to comply with lab accreditation requirements, you need to verify that your detergents are not interfering with the strips and papers. Detergents and surface active agents can interfere with some pH paper by causing a decrease of several pH units in reading. Please test any pH paper you intend to use …
Cleaning Glass Slides for Silane Coating
Q. I am developing a new cleaning process to replace the process we are using for cleaning glass slides before applying Silane coating. We are using strong acid to clean glass slides. I want to use a process where I first use basic aqueous solution, then use DI water to rinse, followed by acidic solution to chelate away metal ions. Then we’ll do DI water rinse, air dry, and finally use oxygen plasma to final clean the glass slide. What acidic aqueous solution and basic aqueous solution can you suggest?
Removing Trace Contaminants of Phenol
Q. We are attempting to validate our glassware washing process and found trace contaminants of phenol remaining after the washing process. Is there another detergent that is able to remove phenol better then Liquinox®?
A. In general, for manual cleaning, Liquinox® should be an excellent choice for removal of phenol residues. For very low level trace analysis, additional rinsing may be required. For routine laboratory cleaning, a triple rinse is typically used. For trace analysis, a 6 time rinse with purified water is typically used. For extreme low level trace analysis . . .
Cleaning Laboratory Glassware by Soaking
Q. Some of our glassware was left soaking in Alconox or Alconox and then bleach for a long period of time. Is this okay? A. Laboratory glassware that is completely submerged in an Alconox® solution is generally ok even with extended soaking. However, if you leave the laboratory glassware partially submerged…
Removing Trace Metals, Inorganics & Organics without Acid?
Q. We are trying to reanalyze our cleaning procedure. Do you have a product that removes trace metals, inorganics and organics without an additional acid rinse? We sample waste water influent and effluent and collect in plastic containers. Please let me know what you would recommend.
A. Organic residues are typically effectively removed by alkaline cleaning. The most robust way to remove trace metals and inorganics is to use an acid rinse. However . . .