NMR Spectroscopy has been applied in analytical laboratories for several decades to analyze compounds in complex pharmaceutical compounds, cosmetics, foods, pesticides as well as in forensic and medical samples. However, quantitative NMR can be used to determine the concentration of several compounds in one sample in only one analysis run – the very big advantage of NMR! Furthermore, authenticity, frauds and contaminations can be identified and determined. As we see, NMR spectroscopy is a very powerful tool for several analytical questions and challenges – but do you know what is possible? We would like to show you the very broad range of fascinating potentialities of NMR spectroscopy.
In the morning, a cup of aromatic Arabica coffee will give you a good start to the day. However, are you sure that you drink an Arabica coffee and not an Arabica/Robusta blend? It is discovered that expensive Arabica beans are often mixed with the cheaper Robusta to allow sellers to get a higher profit margin than just selling pure Arabica. In fact, there are two main types of coffee frauds: the adulteration of pure coffee with substances such as cereals, malt or soy; and the blend of coffee sorts of different economic value like Arabica and Robusta coffee . NMR spectroscopy is a new and time saving way to uncover coffee frauds by comparing different ingredients in only several milligrams of your coffee. And what about those of us who enjoy a sugared Café Latte? Do you know whether it is sugar from cane or beet? Despite what sugar industry officials claim, beet and cane sugar are not alike and labels of most brands do not give any information of the sugar source. However, by NMR spectroscopy the source can be identified, even a 20% mixture of both sugar types. A food product which is very well controlled is milk whose critical importance of food safety and public health lead to high standards of quality and quality control strictly monitored by various federal regulatory agencies. What do you prefer: high-fat or low-fat, lactose-free, fresh or heated milk? With NMR, several quality related aspects such as the content of fat, water, lactose, and lactulose as heating marker as well as additives and the fatty acid profile can be determined. A product which simulates human milk is the infant formula which is designed to be roughly based on a human mother's milk. Here, cow's milk formula is the most commonly used type. Vegetable protein based formulas, especially from soy bean, are used for infants who are allergic to cow's milk or lactose. The chemical purity, ingredient composition and raw material source can be analyzed by a combination of proton (1H), carbon (13C) and phosphorus (31P) NMR spectroscopy. Quality and safety aspects of infant nutrition are of key importance for child health; however, few food producers adulterate food products to increase the financial benefit. One of the best known food scandals is the Chinese milk scandal from 2008 where milk and infant formula were adulterated with melamine with more than 50,000 hospitalized babies and six deaths caused by kidney stones and other kidney damage. Such adulterations can be easily identified by a NMR spectrum . A direct impact of the milk scandal was observed in the change in customer preferences shifting away from milk chocolate to other types of chocolate. At multiple points in the cocoa processing and chocolate manufacturing the intermediate and final products are analyzed for several quality parameters such as fat content or chemical composition. By a combination of 1H, 13C and 31P NMR spectroscopy a holistic control of chocolate can be offered by determining qualitatively and quantitatively among others: fatty acid composition, phospholipids, sugar, caffeine, vanillin, theobromine and other additives. Quality control in food production is increasingly important at every point in the supply chain, from manufacturing and packaging to distribution and retail sale. Vegetable oils - especially high-quality olive oil - have a high vulnerability to adulteration. Edible oils represent the most documented cases of food fraud. Classical quality control of edible oils and fat containing products includes the use of several techniques such as titration and chromatography. Each parameter is analyzed in one analysis step. To improve this process a NMR method was developed to enable a holistic control of edible oils including the analysis of anisidine value, iodine value, saturation grade, peroxide value, free fatty acids, omega-3 fatty acids, fatty acid profile, sterols, diglycerides and other ingredients by requiring only 200 mg sample amount. This sample amount gives important information on chemical modification of native oil components or of contamination entries during extraction and refining. Furthermore, NMR spectroscopy provides answers to the following questions: What is the vegetable source of this lecithin? Do I drink a premium or a discount soft drink brand? Which inorganic anions and cations are present? How is the quality of the wine I am drinking? And how high is the blood alcohol concentration after I finish drinking the excellent wine? Can silicone migrate from packaging material into the product? What is the candle material composed of – palm oil, stearin or bee wax? How much glycerin, triglyceride, silicone, ethanol, and polyethylene glycol (PEG) can be found in skin cream and shower gels? What part of the aloe vera plant was used for the cosmetics – only the inner gel or the whole leaf? How much fluoride is inside my toothpaste? Is the produced pharmaceutical product pure and how does it react concerning alternating conditions such as pH, humidity, storage, or temperature? Is there an impurity and if so, what is it? The answer to all these questions is NMR spectroscopy, a very powerful tool for target and non-target analysis – our scientific service. We are Spectral Service, an independent private laboratory which is GMP- and GLP-certified as well as approved by the US Food and Drug Administration (FDA).