Metrohm 797 VA Computrace - Manual (Page 12)

Table of contents
797 VA Computrace – Software
VIII
Electrolytes ................................................................................ 259
Standard solutions ..................................................................... 259
Samples ..................................................................................... 260
Blank values, contamination ...................................................... 260
Selection of VA Measurement mode.......................................... 260
9.6 Voltammetric problems....................................................... 262
Low background current or unstable baseline............................ 262
Curves with high noise............................................................... 263
SqW Problems ........................................................................... 263
Standard addition curves are not reproducible........................... 264
Peak displacement ..................................................................... 265
No peak found........................................................................... 265
Peak is in the highest μA range.................................................. 266
Double peak .............................................................................. 266
Standard addition peaks displaced............................................. 267
No addition ............................................................................... 267
Spikes / signal jump in voltammogram....................................... 268
Oxygen interference .................................................................. 268
Unsuitable bridging electrolyte in the reference electrode.......... 269
Overloading of the working electrode........................................ 269
Disturbances at the HMDE through gas formation..................... 271
Complex formation.................................................................... 272
Peak on highly curved baseline .................................................. 273
Peak overlapping ....................................................................... 273
Calibration with chemically non-isoformal standards ................. 274
Results not reproducible ............................................................ 274
Software license.................................................... 276
Declaration of conformity – Software validation .. 278
Index ..................................................................... 279