Optimization of the power supply and temperature control algorithm for a second-dimension temperature programming system used in comprehensive two-dimensional gas chromatography

This study evaluates the relationship between the power supply output (voltage (V), current (I), power (W)), used for heating a second dimension (²D) column, and the maximum heating rate and temperature offset achievable by custom built ²D temperature programming system (²DTPS). The influence of the gas chromatograph (GC) oven temperature, ²D column flow rate, and ²D column dimensions when heating the ²D column were also explored. This data provided the minimum power needed for heating a ²D column (normalized to its length), based on the heating rate or temperature offset relative to the first dimension (¹D) column. During the study, optimization of the temperature control algorithm was also carried out to expand the dynamic range of the heating rate for a single power supply output (V, I), while maintaining a temperature deviation of < 0.75 °C between the measured temperature and temperature setpoint. This simplified the power supply specification recommendation to voltages which provide 1.5 A for heating rates and maximum temperature offsets below 28 °C/s and 70 °C, respectively, and 1.9 A when higher heating rates or temperature offsets were needed.