**1. Introduction**

Food safety has become an important key issue worldwide, because of the emergence of several new chemical hazards present in food [1]. In addition to that, maintaining food safety has become very challenging at the operational level, as production of food and their consumptions are currently involved in a series of events that must be adequately accomplished to ensure the safety of food [2]. Therefore, food safety has become an increasingly important public health issue all over the world and due to which governments are escalating their efforts to improve and ensure food safety. These efforts can also be recognized in response to a growing number of food safety problems and

increasing consumer health safety concerns [3]. A very well-know proverb from nutritionists or dietitians is "we are what we eat". Definitely, it does not mean that if we eat apple we become apple, but for good or for ill, the components we eat must be incorporated, transformed, and/or excreted by our bodies. Because, food is an indispensable ingredient of life, and access to food is often the limiting factor in the size of a given populace [4]. There are several incidents of food safety outbreak, which has received major attention from all parts of the world such as occurrence of benzene in carbonated drinks (UK), foods contaminated with pesticides (Japan), presence of dioxins in milk products and pork sample (Belgium), incidence of pesticides in soft drinks (India) and occurrence of melamine in dairy products (China). Such incidents have made people distressful of their food consumption worldwide [5]. In addition to that, such contemporaneous incidents are growing concerns, mainly because of mass production of agronomic products and industrialization at a very fast pace to meet the requirement of current population. Moreover, it has been considered that mainly increasing worldwide population is making farming people to force mass production of agronomic products without giving ample consideration to the safety and quality of food produce. In addition to that, changes in life style patterns of consumers have been called responsible for food safety hazards [6]. Due to fast-paced urbanization, food products such as ready-to-eat, processed food and junk foods has increased, but due to rise in application of chemicals usage, such processed food has also come under the scanner of food safety professionals [1, 7].

Moreover, the scope, relevance, and level of food safety and testing have never been in such complexity than in today's global marketplace. In recent years, a novel technology UPLC-MS has been developed to estimate the food contaminants as well as food components with better accuracy, sensitivity, precision, and high throughput. In addition to that, this advanced novel technique provided the platform to estimate different analytes at very lower levels, with better accuracy, and more importantly in less time. Moreover, the uniqueness of UPLC-MS has marked several applications to food safety. Various food safety parameters such as residual analysis, vitamins, amino acid, metabolite identification, adulteration, forensic testing, toxicity studies, phytoconstituents analysis, pesticide in agriculture, antibiotic residue, hormones, dyes and pigment analysis can be performed by using UPLC-MS [8, 9]. In addition to that, wide range of analysis makes UPLC-MS as an integral part of food safety laboratory around the globe. Moreover, in this chapter a detailed study and exploration has been made for better understanding of principles and applicability of UPLC-MS in food safety.
