Detection of Melamine in Gluten, Chicken Feed, and Processed Foods Using Surface Enhanced Raman Spectroscopy and HPLC

Abstract

Melamine, a nitrogen-rich chemical, was implicated in pet and human food recalls in 2007, which caused enormous economic losses to the food industry. In this study, melamine concentration in wheat gluten, chicken feed, and processed foods (that is, cake and noodle) was measured by surface enhanced Raman spectroscopy (SERS) in combination with SERS-active substrates. SERS was able to rapidly detect 0.1% melamine in wheat gluten, 0.05% in chicken feed, 0.05% in cakes, and 0.07% in noodle, respectively. A partial least squares (PLS) model was established for the quantification of melamine in foods by SERS: R= 0.90, RMSEP = 0.33. In addition, SERS results were verified by HPLC analysis based on a simplified FDA method. Compared with HPLC, the SERS method is much faster and simpler, requires minimum sample preparation, but still yields satisfactory qualitative and quantitative results. These results demonstrate that it is an applicable approach to use SERS to screen foods, eliminate presumptive negative samples of melamine contamination from the sample population, and then verify presumptive positive samples using HPLC protocols. Combining these 2 methods could provide a more rapid and cost-effective way for monitoring melamine contamination in increasingly large numbers of imported foods and feed products.

Differentiation of bacterial strains by means of surface enhanced FT-Raman spectroscopy

“…Infrared and Raman spectroscopies have been extensively applied in various research areas: for detection of food toxicants and chemical adulteration [11][12][13], bioprocessing and fermentation monitoring [14][15][16][17], enzyme activity [18], microorganism identification and segregation [19][20][21][22][23][24][25][26], microbial cell injury identification [27,28], virus identification [29], and prion structure elucidation [30].…”

Raman spectroscopy and its applications

“…Análisis de la inclusión, la química y la identificación mineral [47,48],  Ciencias de la alimentación. Identificación y cuantificación de no saturación, contenido de grasa, etc [49][50][51][52][53],  Determinación de los componentes del medio ambiente [54,55],  Industria del cristal y porcelana.…”

Application of Tandem Mass Spectrometry for Analyzing Melamine

“…Other studies have introduced alternative qualitative methods, such as surface-enhanced Raman spectroscopy (SERS), matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS), and direct analysis in real time (DART) coupled with time of flight mass (TOFMS). SERS has been used to screen MEL in a number of food matrices including gluten, chicken feed, and processed foods (Lin et al, 2008). Vail et al, (2007) used DART ion source coupled with TOFMS to detect MEL in pet food.…”

“…Retention times are prolonged for polar compounds and sensitivity is enhanced in mass spectrometry. Other methods use reversed-phase C18 or C8 columns (Lin et al, 2008;Venkatasami & Sowa Jr, 2010;Ibánez et al, 2009;Lutter et al, 2011). Recently, UPLC has been introduced in this field.…”