13C/12C isotope ratios of organic acids, glucose and fructose determined by HPLC-co-IRMS for lemon juices authenticity

Determination of carbon isotope ratios for honey samples by means of a liquid chromatography/isotope ratio mass spectrometry system coupled with a post‐column pump

“…values (see below). The sodium peroxodisulfate and phosphoric acid concentrations used with both interfaces were 0.26-1.5 and 0.5-1.5 M, 9,10,14,15,21,23,26,35 respectively; that is, the concentrations that we used in this study were similar to the previously reported concentrations.…”

“…In previous studies, the flow rates of sodium peroxodisulfate and phosphoric acid were 0.02–0.05 and 0.03–0.05 mL min −1 , respectively, for systems using the LC IsoLink interface. In contrast, the mixing flow rate of sodium peroxodisulfate and phosphoric acid used with the LiquiFace interface was 0.6 mL min −1 ; that is, the flow rate used with the LiquiFace interface was higher than that used with the LC IsoLink interface. This difference is due to the fact that these interfaces use membranes with different i.d.…”

“…Despite these problems, LC/IRMS has been used to analyze compounds in various sample media, including caffeine in beverages; 13 organic acids, glucose, and fructose in lime and lemon juices; 14,15 glycerol and ethanol in wine; [16][17][18] vanillin in chocolate bars and snack foods; 19 glyphosate and aminomethylphosphonic acid; 20 sulfonamides in pharmaceuticals; 21 glucose in blood plasma; 22 amino acids; 23,24 steroids; 25 and sugars (glucose, fructose, disaccharides, trisaccharides, and oligosaccharides) in honey. [26][27][28][29] Honey is a highly nutritious functional food composed mainly of glucose, fructose, minor sugars, organic acids, amino acids, vitamins, and minerals.…”

The application of stable isotope ratio analysis to determine the geographical origin of wheat

“…In recent years, mislabelling and adulteration are still two of the most serious problems in many areas of food market, they not only infringe the rights of the consumers, but also threaten the livelihood of honest traders (Guyon et al, 2014;Nietner, Haughey, Ogle, Fauhl-Hassek, & Elliott, 2014;Tosun, 2013Tosun, , 2014. Under this kind of phenomenon, consumers are increasingly attracted to foodstuffs that declare not only their composition but also their geographical origin, such as products with a Protected Denomination of Origin (PDO).…”

Geographical traceability of wheat and its products using multielement light stable isotopes coupled with chemometrics

“…Geographical origin of a wide range of agro‐products has been successfully discriminated using a combination of chemometrics and several analytical techniques such as gas chromatography coupled to mass spectrometry (GC‐MS) to discriminate white rice through profiling of volatile organic compounds; inductively coupled plasma mass spectrometry (ICP‐MS) to discriminate geographical origin of wheat, tea, etc; and isotope ratio mass spectrometry (IRMS) to distinguish cereal, milk, meat, and honey . Moreover, spectroscopic techniques (NIR, NMR, FTIR‐ATR) and separation technique high‐performance liquid chromatography (HPLC) have been applied to various food products such as wheat, honey, and lemon juice to investigate the authenticity and geographical origin of these products . However, IRMS is one of the most reliable, highly sensitive, rapid, and broadly used technique, as it provides a precise and accurate measurement of variation in the natural isotopic abundances of light stable isotopes …”