A HOMEMADE SPIN COATER BASED ON ELECTRONIC WASTE: A VERSATILE AND LOW COST ALTERNATIVE. High-precision equipment generally represents a significant portion of a laboratory budget, leading the access by laboratories with limited financial resources difficult. Then, adaptation of materials such as electronic trash may be a key factor to overcome financial obstacles. As the technological advancement brings with it an increase in the disposal of pieces of equipment considered obsolete, these pieces however can still be used in the construction of new equipment. The present work shows the employment of a scrapped computer HD in addition to an Arduino microcontroller and other electronic components to build a low-cost spin coater. The thickness of films obtained in the handmade equipment presented approximately five percent of difference in relation to films obtained in a commercial equipment.

This review reports the use of solid amalgam electrodes in the electroanalytical determination of organic and inorganic compounds. The different types of amalgam electrodes are presented, and attention is paid to solid amalgam electrode, and here is presented details about the pre-treatment for activation and renovation and also possible modifications in its surface. The wide potential range, higher signal-to-noise ratio, mechanical stability enabling their application in flowing systems, and principally their resistance toward passivation, indicate that the solid amalgam electrodes are environmentally friendly alternatives to mercury electrodes, without loss in the sensitivity and reproducibility in voltammetric responses.