Chemicals play a vital role in the agricultural and food processing industry. These chemicals improve the quality, quantity, and durability of food products. Chemicals added to food products comprise fertilizers, pesticides, preservatives, natural sweeteners, antioxidants, synthetic vitamins, and colorants.
An excess of chemicals contained in the food might harm the consumer. Most countries have a set standard for the number of chemicals that are allowed in food products. Analytical methods ensure that the prescribed levels in the agriculture and food industry are maintained.
Toxic levels of natural acids and high levels of carbohydrates have to be regulated in food products.
High-Performance Liquid Chromatography (HPLC) is a food testing method developed to analyze food samples and detect the different chemical components and their quantity. It was developed in the 70s and by the 80s came to be used commonly in chemistry labs.
This type of chromatography helps in the breaking down of complex mixtures. The broken-down particles are then identified and assessed by data handling systems. The method is suitable for compounds of limited thermal stability.
The chromatography offers a sensitive and selective analysis of food products as it can inject large sample amounts. The US Food and Drug Administration or FDA has recommended this Chromatography method to analyze non-volatile and polar compounds.
It is vital in food testing, developing vaccines, pharmaceutical manufacturing, and environmental monitoring. Modern methods have evolved liquid chromatography to compete with the already successful method of gas chromatography. Today, HPLC provides features like:
- Speed of separation.
- High resolving power.
- Accurate quantitative measurement.
- Continuous monitoring of the column effluent.
There are various types of HPLC models like:
- Normal Phase Chromatography
- Size Exclusion Chromatography
- Ion-exchange chromatography
- Displacement Chromatography
- Reversed-Phase Chromatography
There is a growing requirement of professionals with knowledge of analytical chemistry. The chemical industry is a million-dollar business with a renewable job requirement. There are new developments in chromatography, and its research field is simultaneously flourishing.
Harmful pesticides used in the early stages of agriculture are hard to detect. There is a growing concern among environmentalists as pesticides affect the pH balance of the soil. HPLC is highly recommendable for the analysis of low volatile compounds and those that are unstable when heated.
Citric acids and sorbic acids are commonly used preservatives in the food industry. Food processing companies add citric acid for its fresh, acidic flavor and succinic acid for its salty and bitter taste.
Acidulants also act as a buffering agent to control the pH during food testing. HPLC and UV-visible diode-array detection (UV-DAD) is effective in analyzing citric acids. Retention time and spectral data are efficient identification tools.
Acesulfame, Aspartame, Saccharin are the three major artificial sweeteners used in food products. These chemicals found in biscuits, chocolates, soft drinks, and cakes are toxic in quality.
Thereby, the legislation has laid strict regulations for the usage of artificial sweeteners. Chromatographic conditions suitable for testing artificial sweeteners are many.
One among them is the use of High-Performance Liquid Chromatography with automated on-column derivatization and reversed-phase chromatography. An additional identification tool can be UV-spectra.
Food colorants re-dye the food to mask aging and decay. HPLC methods rely on ion-pairing reversed-phase or ion-exchange chromatography. UV absorption is favored as a detection method.
The UV absorption maxima of colors are highly characteristic. Colors at maximum sensitivity and selectivity can be detected using light output from the detector lamp set high for the entire wavelength range.
Toxic compounds produced by fungi are known as mycotoxins. Mycotoxins develop when food items have a favorable growth for fungi. Mycotoxins are detected using thin-layer chromatography (TLC).
The higher separation power and shorter analysis time of High-Performance Liquid Chromatography make this method suitable. The chromatography method uses multisignal UV-visible diode-array detection and fluorescence detection. UV spectra can act as an additional identification tool.
Amino acid composition of meat products can trace the origin of the meat and detect adulteration if any. HPLC and automated online derivatization method can detect amino acids as it has a short analysis time and relatively simple sample preparation.
The High-Performance Liquid Chromatography method, when paired with pre-column derivatization and fluorescence detection, derives optimum results.
Food carbohydrates have a wide range of chemical reactivity and molecular size. Carbohydrates do not contain chromophores or fluorophores. As a result, normal UV-visible and fluorescent techniques cannot detect carbohydrates in food testing.
Today, refractive index detection and electrochemical detection can analyze carbohydrate content in food products.
HPLC is a multi-faceted industry with opportunities from all over the world. In a world of Industrialisation and technology, High-Performance Liquid Chromatography combines both schools of knowledge to create innumerable job opportunities. To the new generation, it is a field with excessive scope for research and development.