Abstract Metals can contaminate the environment and increasingly affect ecological systems and public health worldwide. Cu(II) and Pb(II) ions play a significant part in increasing the cancer rate, since their amounts are higher in cancerous patients than in healthy individuals. Electrochemical methods have been extensively used for analyzing biological, beverages and food samples to estimate Cu(II) and Pb(II). The present study has employed LSASV for Cu(II) and Pb(II) determination in female patients (suffering from breast-cancer) cancerous blood serum samples. Optimized conditions for analysis have required: Gc, with an eacc of -0.2 V and a tacc of 400 s, as WE; 0.1 M AB (pH 5.1) as SE, at a stirring rate of 9 rpm and SR of 100 mV/s-1; Ag/AgCl as RE; and a Pt wire as CE. Under the optimized conditions, the cost-effective procedure was successfully applied for Cu(II) and Pb(II) determination in cancerous human serum. LOD was in the range of ppb. The analysis indicated higher Cu(II) and Pb(II) levels in cancerous female patients than in the healthy ones. Therefore, a strictly controlled diet is recommended.

Abstract The research article is based on biodiesel synthesis by the transesterification of waste cooking oil with methanol in the presence of heterogeneous catalysts prepared from different marble. Eight samples of marble were successfully converted into potential catalysts by calcination. The thermal treatment of waste marbles at 300oC-1000oC converted the metal carbonates (CaCO3) to metal oxides (CaO). The calcined marble was analyzed by chemical tests, flame atomic absorption spectroscopy (FAAS), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction studies (XRD). The presence of CaO in these catalysts made them highly reactive for biodiesel synthesis. The basicity and percentage of calcium in marble catalysts were calculated to know their basic strength. The transesterification was performed by fast stirring using waste cooking oil, methanol and nine different types of marble catalysts for 5 min at five different conditions, i.e., room temperature, hot plate stirring, solar ordinary irradiations, solar concentrated reflected irradiations and solar concentrated refracted irradiations. The solid catalysts were easily separated from the product for re-use. All marble catalysts were found to be active and basic except one namely silver pun (I). The production of biodiesel was confirmed by ASTM standards, TLC examination and by gas chromatography (GC).