Abstract
The interaction of silica–titania xerogel with triphenylmethane dyes (pyrocatechol violet, chrome azurol S, eriochrome cyanine R) has been investigated to create a new sensor material for solid phase spectrophotometric determination of food oxalates. The complex forming reaction between xerogel incorporated titanium(IV) and triphenylmethane dyes has been studied; half-reaction periods, complex composition, equilibrium constants, and xerogel sorption capacity have been calculated for each dye. Eriochrome cyanine R (ECR) is characterized by the shortest half-reaction period, the smallest equilibrium constant, and the greatest capacity; it has been chosen for the sensor material construction because titanium(IV)-ECR complex is formed faster and can be destroyed easier than other studied complexes. The interaction of this sensor material with oxalates has been described: the presence of oxalates causes sensor material discoloration and the absorbance is used as analytical signal. The analytical range is 35–900 mg/L (LOD 10.5 mg/L, n = 7). High concentrations of interfering inorganic anions, organic acids, and sucrose did not affect oxalate determination. Proposed solid phase spectrophotometric procedure has been successfully applied for the determination of oxalates in food samples (sorrel, spinach, parsley, ginger, and black pepper) and the results are in good agreement with HPLC oxalate determination.
Highlights
Oxalates can be an important health risk, because consumption of large amounts of oxalate causes secondary hyperoxaluria, which often leads to kidney stone formation [1,2]
In the present work we studied the interaction of silica–titania xerogels with triphenylmethane
In this work we studied the interaction between silica–titania xerogel and triphenylmethane dyes
Summary
Oxalates can be an important health risk, because consumption of large amounts of oxalate causes secondary hyperoxaluria, which often leads to kidney stone formation [1,2]. An excessive oxalate intake can be responsible for acute renal failure and it reduces the bioavailability of calcium and magnesium [3]. The main sources of dietary oxalate are high-oxalate containing plants [1]. Given the risks of oxalate overconsumption, oxalates are routinely monitored in food quality control
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
