Examination of pesticides in food

Postoji mnogo analitičkih metoda koje se koriste za detekciju ostataka pesticida u hrani. Sve one uključuju pripremu uzoraka, ekstrakciju, pročišćavanje, razdvajanje i detekciju određenog spoja. Nakon što je pesticid ekstrahiran iz uzorka odvaja se od ostalih suekstrahiranih spojeva ili plinskom (GC) ili tekućinskom kromatografijom (LC), a rjeđe tankoslojnom (TLC). Svim kromatografskim metodama zajedničko je postojanje nepokretne (stacionarne) i pokretne (mobilne) faze. Plinovita ili tekuća mobilna faza nosi komponente uzorka kroz stacionarnu fazu, a odjeljivanje se temelji na razlikama u brzinama kretanja komponenata kroz stacionarnu fazu. Završni korak analize (detekcija) omogućava nastajanje električnog signala koji je proporcionalan intenzitetu neke osobine mobilne faze ili supstance koja se eluira pa se može koristiti za mjerenje količine pesticida koji prolaze kroz kolonu. Sve tehnike koje se koriste i dalje će se poboljšavati, a teži se povećanju broja pesticida koji se mogu odrediti jednom metodom u jednom uzorku.There are a lot of analytical methods used for detection of pesticide residues in food. All of them include sample preparation, extraction, purification, separation and detection of a particular compound. Once the pesticide is extracted from the sample it must be separated from other extracted compounds with gas (GC) or liquid chromatography (LC), rarely with thin layer cromatography (TLC). For all cromatographic metods in common is the existance of fixed (stationary) and mobile phase. Gaseous or liquid mobile phase carries the sample components through the stationary phase, so separation is based on differences in speed of movement of components through the stationary phase. The final step of the analysis (detection) allows the formation of an electric signal that is proportional to the intensity of some features of mobile phase or a substance that is eluted and can be used to measure the amount of pesticides that pass through the column. All the techniques used will continue to improve with tendation to increase the number of pesticides that can be determined with one method in one sample