An electrochemical detector with a dropping mercury electrode for high-performance liquid chromatography

The electrochemical flow-through cell described has an active volume of less than 1 μl, and incorporates a dropping mercury electrode with drop times of about 0.05 s. Its performance as a detector for high-performance liquid chromatography is assessed for p-nitrophenol and nitrobenzene. The detection limits are 4–5 ng; the relative standard deviation of the peak height is better than 5% for the range 5–150 ng. The dependence of the response on flow rate, mercury pressure and drop time is described.