Development of a low-cost semi-automated robotic orthophosphate system for batch analysis.

Monitoring the level of nutrients in soil and their availability for crops can be time-consuming or require expensive instrumentation. This work describes a low-cost (<€500) portable, semi-automated colourimetric orthophosphate (PO) analyser supplemented with 3D printed parts. Colour development was based on the phosphomolybdenum blue formation coupled with spectrophotometric detection using a low-cost LED-photodiode assembly.

Novel determination of Cd and Zn in soil extract by sequential application of bismuth and gallium thin films at a modified screen-printed carbon electrode.

This study describes a novel electrochemical technique for the detection of bioavailable cadmium(II) (Cd) and zinc(II) (Zn), in real soil samples. This was made possible by the sequential deposition of bismuth and gallium thin films on modified screen-printed carbon electrodes (SPEs). A range of graphitic modifications were evaluated, and a reduced graphene oxide/graphitic carbon nitride (RGO/g-CN) modification proved most suitable.