pHuvette is a cuvette with an embedded optical pH sensor. You pHuvette converts your spectrophotometer into an accurate, drift free pH meter.

 

pHuvette is easy to use: just add your sample, measure the absorbance at 3 wavelengths and calculate pH.  The pHuvette is especially accurate for measuring reaction rates where there are pH changes. 

 Download Application Notes!

The pH sensing surface is a nano-material especially formulated to trap pH indicator molecules in a cage like structure. The cage is hydrophilic, so hydronium ions freely diffuse through the film. The trapped brom-cresol green ions change color when they bind or dissociate with hyronium ions.

 

The spectra below show the absorbance spectra of a pHuvette at several levels of pH taken with an Ocean Optics USB4000. The baseline is pH = 4.0; the highest curve is pH = 10.0

 

The pH is calculated from the ratio of absorbances at 620nm to 470nm.  The absorbance at 750nm is used to correct for any baseline drift caused by changes in the cuvette position, lamp drift or particulates or animals in the light path.

 

Animals? Yes, the pHuvette is ideal for measuring respiration rates of aquatic plants and animals. The indicator is safely trapped in the nano-material and does not affect the animals. Just use the stopper to create a closed environment and monitor the uptake or release of CO2 by its affect on pH. You will need to know the level of at least one other parameter of the carbonate system… alkalinity, pCO2 or total CO2 in your starting sample.

 

The pHuvette is re-usable. That’s cost effective! Simply rinse the pHuvette with de-ionized water between samples. It can be stored wet or dry. Just make sure the pH sensing material is fully hydrated when you use it.

 

The technology is flexible, literally!  We can install the sensor in all kinds of devices… micro-well plates, petri dishes, small, medium and large cuvettes, respirometers of any size, aquariums, pipes and diver held underwater spectrometer cases! We also design fiber optic probes to couple to those odd shaped vessels. Call us and we will configure a complete package system for you today.