<title>pH influence on near-infrared spectra of glucose</title>

Abstract

The objective of this study was to determine the effect of pH on near-infrared (NIR) (2.0-2.5 tm ) spectra of glucose in phosphate buffered saline (PBS) solution within a tight range of control similar to what is found in many mammalian organisms and cell cultures. It is known that the NIR water spectrum in this wavelength range (2-2.5 tim) may be altered by pH, and it has been shown that glucose absorbance spectra do not change with pH when an equal reference pH is available. However, because the glucose absorbance spectra rides on the water spectra, changes in the spectral characteristics did occur. These effects need to be considered, in particular for single beam glucose spectra.