Charge

Mass spectrometry is an analytical technique that involves fragmentation and ionisation of gas phase molecules. From piecing together the fragments of different mass to charge (m/z) ratios, the analyte structure can be deduced. In this video, the internal components of a Quadrupole-Time of Flight mass spectrometer is illustrated and explained. Analysis of caffeine (C8H10N4O2) is animated showing its fragmentation. Fragment ions travel down the flight tube and separate according to m/z ratios in which lighter ions arrive first, while heavier ones arrive later. Animation is shown in the zoomed-out, zoomed-in and sample views. The mass spectrum is also shown with fragments identified.

How does electroplating work? It is a process where you usually take an object made of one type of metal, and cover it with a thin layer of another type of metal. Usually, precious metals like gold, silver, or platinum are the metals that are electroplated. In an electroplating cell, electrons are removed from one of the metals, which is an oxidation process that happens at the anode. This causes the metal to develop a charge turn into an ion, and allows it to dissolve in the solution. Then, at the cathode, reduction takes place, and the metal ion turns into a neutral atom, and sticks to the surface of the other metal.

Capillary electrophoresis is a separation technique in which charged species are separated, based on charge and size, by their different rates of migration in an electric field. The capillary is made of negatively charged fused silica inner wall which forms an electrical double layer with cations in the running buffer. These cations in the electrical double layer move towards the negative cathode and hence the overall direction of flow also known as the electroosmotic movement is towards the cathode. The sample is placed in the running buffer. All analytes will move with the same electroosmotic velocity driven by the running buffer but with different electrophoretic velocity which allows separation. Order of elution would be highest charge and smallest cations would elute first, followed by neutral species and the last to elute would be the highest charge and largest anions. Chemistry Movies & Molecular Animations are also available on the "Animol" app on Apple App Store and Google Play Store!