Measurement of organic acids with a n-silicon semiconductor anode

Instability of current followers in potentiostat circuits

“…D. K. Roe (6) has presented a current follower with a low input impedance. The reduction was accomplished by unique circuitry which also allows simple control of the gain.…”

“…The electrode has also been shown to be applicable to the measurement of HF in either H2SO4 or H3PO4 mixtures (5). An additional application has been made to the measurement of organic acids including acetic, citric, oxalic, and tartaric (6). The combination electrode appears capable of measuring acids which have Ki0n values greater than 1 X 10-6 or slightly lower than acetic acid (K¡on = 1.76 X -5 at 25.0 °C).…”

Present status of the N-silicon/stainless steel combination electrode for acid determinations

“…After standardizing, obtain the meter reading of each acid solution and relate it to a previously prepared calibration curve. One of the critical steps in the measurement involves adjustment of the temperature compensation knob for any noticeable changes in temperature (6). As the temperature compensation knob is marked only in 5°intervals, a protractor and pencil can be used to indicate degree markings on the scale between 20 and 30°-the usual operating range.…”

“…Titrated by method of Moskowitz and Dasher (9). 6 Electrode calibrated with 0.050/V H2SO4 containing 0.010 g Cu2 + and 1.10 g NH4F per 100 ml. in HCI; 40% FeCI3 made approximately 2/V in HCI arated along with S1F4 during concentration of the raw phosphoric acid by evaporation.…”

“…surement of organic acids including acetic, citric, oxalic, and tartaric (6). The combination electrode appears capable of measuring acids which have Ki0n values greater than 1 X 10-6 or slightly lower than acetic acid (K¡on = 1.76 X -5 at 25.0 °C).…”