Spectral study of bichromatics: Biuret-protein and glucose-hexokinase reactions as visible-ultraviolet models for turbidity

A Clarifying Solution for Hypertriglyceridemic Serums

“…That also assumes that the turbidities have some kind of constancy with respect to particle size as well as wavelength. To demonstrate this phenomenon, a recent study was reported in which pure protein solutions were contaminated with total parenteral nutrition solution and results obtained using biuret reactions were compared with those of the same solutions without the presence of the turbidity contaminating interference (65). In viewing the comparative results obtained, it became obvious that the measurements were distorted by the presence of turbidity and that these distortions varied significantly when the two side wavelengths employed differed, as suggested above, one from the other with corrective wavelengths selected on either the red or the blue side of a similar peak wavelength.…”

“…Therefore, if the side wavelength is chosen bathochromic to the peak wavelength of the reacted analyte, too little absorbance will be subtracted as a corrective effort. In contradistinction, if the side wavelength is hypsochromic to the peak wavelength of the reacted analyte, too much absorbance will be subtracted in this corrective effort (65). Therefore, in the case of the side wavelength chosen for turbidity correction, it may be necessary to have a factor on the absorbance read (78) inasmuch as the side wavelength absorbance of the interference is different than the primary (peak) wavelength absorbance of the interference.…”

“…If one were to consider how the effect of hypertriglyceridemia on spectrophotometric measurement could be either obviated or removed or the turbidity clarified, perhaps the simplest first approach would be serum blanking (39,(63)(64)(65). The preparation of a sample blank by eliminating one critical ingredient so that the measurement of the reaction for quantification would be made possible is certainly simple even though it could require the use of twice the amount of serum.…”