$1\mathrm{.}1.$ Describe the CHNS elemental analysers.

$(2)$

$1\mathrm{.}2.$ Everyone's top priority is eating safe food. Government regulations and public awareness have increased as a result of the recent prevalence of contaminants and adulterated, counterfeit, or fraudulent food, such as arsenic $($As$)$ in baby food or selenium $($Se$)$ in solid and liquid supplements, as well as purposeful or unintentional adulterants, like lead $($ Pb