When one thinks of chemistry, the first thing that pops inside his/her head is the mental image of a chemical laboratory or similar environment. Giving the fact that chemistry is primarily a practical science, lab work is the inevitable part of chemical education. However, the majority of elementary schools and high schools in Serbia usually do not possess the necessary resources (e.g., space, glass, chemicals) to provide their pupils with deserved practical work in order to gain elementary lab skills.
Analytical methods based on volume measuring are named titrimetric or volumetric methods. In titrimetric analyses, we add a reagent of exactly known concentration to a solution of analyzed compound until they completely react – a process called titration. They are highly accurate and precise, rapid and nowadays automated.
Analytical chemistry gives you the ability to ask and answer the questions such as "What is something made of?" or "How much of each constituent is present in the sample?" The main purpose of analytical chemistry is to identify or quantify analytes in the sample. For example, give the analytical chemist a cup of coffee and he/she will tell you if there is caffeine in it, how much sugar you've added or what elements is your cup made of.
Polycyclic aromatic hydrocarbons (PAHs) are widespread contaminants generated primarily during the incomplete combustion of organic materials (e.g. coal, oil, petrol, and wood). These organic compounds are mostly made of hydrogen and carbon in the form of two or more fused aromatic rings. PAHs have been proven to be harmful to human health and should be avoided.