Thermal decomposition of pyridoxine: an evolved gas analysis‐ion attachment mass spectrometry study

Abstract

The calculated kinetic parameters are important for predicting the thermal stability of pyridoxine vitamer. The estimated lifetime (t(90%,25°C) ) of 1.7 × 10(-2) years in nitrogen was also obtained from the EGA-IAMS experiment.

A review of stability issues associated with vitamins in parenteral nutrition

“…Juhasz et al 46 examined the thermal decomposition of pyridoxine. In this experiment, they calculated the amount of time it takes to reach 90% pyridoxine recovery at 25°C to be 1.7x10 -2 years (approximately 6.2 days).…”

Comments on “Thermal decomposition of pyridoxine: an evolved gas analysis‐ion attachment mass spectrometry study”. About the application of model‐fitting methods of kinetic analysis to single non‐isothermal curves

“…In a paper recently published in this journal, [1] the thermal decomposition of pyridoxine was studied by means of evolved gas analysis-Li + ion attachment mass spectrometry (EGA-Li + IAMS), which is a technique with great potential for the kinetic study of thermal decomposition reactions. In that paper, the decomposition products were identified and, in addition, a kinetic analysis of the process was carried out.…”

“…The extent of conversion at a certain time or temperature was then determined by integrating the area under the TIM curve from the beginning of the signal until the selected time/temperature. [1] With that information, the kinetic parameters driving the reaction, i.e. the activation energy and the pre-exponential factor, were calculated by fitting the experimental data extracted from the TIM curve to a first-order kinetic model.…”

“…The simulation was performed using a Runge-Kutta 4 th order numerical integration method, programmed using the Mathcad engineering calculations software (Mathsoft; PTC, Needham, MA, USA). For the sake of comparison, the simulated curve has been analyzed using the same model-fitting method employed in Juhasz et al [1] Figure 2 shows the plots resulting from fitting the data to some widely used ideal models. The activation energies and pre-exponential factors calculated from the plots, as well as the regression coefficients for each case, have also been included in the figures.…”

“…Plots obtained from fitting the simulated curve in Fig. 1 to some of the most widely used kinetic models by means of a differential model-fitting procedure, as employed by Juhasz et al [1] The activation energy is calculated from the slope of the curves, and the pre-exponential factor from the intercept. of the fits in Fig.…”