Abstract: A method for the detection of the presence of lead in a solid substrate suspected of containing lead, including the steps of: contacting a solid substrate suspected of containing lead with a reagent composition including a liquid medium and halide reagent capable of reacting with lead to form a lead halide perovskite, the substrate being selected from painted surfaces, glass, metals, electronic products, soil, dust, waste, food and feed products, personal care products, cleaning products, and rock; and subjecting the substrate to a light source with a wavelength that is shorter than the emission wavelength of the lead halide perovskite, and detecting the light emittance. The method allows the detection of lead in high selectivity in low amounts. Also, a test unit and test kit suitable for use in the method.

Abstract: The present invention provides a method for the synthesis of optically pure ?-aryl propionic acid derivatives comprising subjecting the corresponding racemic ?-aryl propionic acid derivatives to high sheer or impact forces, such as grinding.