A colorimetric assay for vanillin detection by determination of the luminescence of o-toluidine condensates

Abstract

Vanillin (4-hydroxy-3-methoxybenzaldehyde), a food additive with rich milk flavor, is commonly used in the food, beverage and cosmetic industries. However, excessive consumption of vanillin may cause liver and kidney damage. Therefore, methods for detecting and controlling the level of vanillin in food, especially in infant powder, have important practical significance. In this study, we established a colorimetric assay for vanillin detection. The detection was performed under high-temperature and acidic conditions, which can induce the reaction of the aldehyde group of vanillin with the amino group of o-toluidine. The resulting product had a maximum absorption at 363 nm, which was quantified by a UV spectrophotometer. This assay had a limit of detection (LOD) of 1 pg mL−1 and a linear range between 1 μg mL−1 and 100 μg mL−1. The average recoveries at three spiked levels were in the range from 91.1% to 101.6% with a relative standard deviation (RSD) of 4.62% ~ 7.27%.

Recent Research Progress on Lignin-Derived Resins for Natural Fiber Composite Applications

“… An illustration of the shear lap joint test of bio-based resins with CNF films ( a ) and cross-sectional SEM images of the specimens for PVA-lignin ( b ) [ 35 ] and PEO-lignin resins ( c ) [ 15 ]. …”

“…The higher toughness, hydrophobicity, and adhesive behaviors can be applied for natural fiber reinforcement applications. [35] and PEO-lignin resins (c) [15].…”

“…Most of the VN mainly extracted from wood, and it is commonly soluble in ethanol [ 11 ]. It is widely used in various applications such as cosmetics [ 12 ], pharmaceuticals [ 13 ], flavorings in foods [ 14 , 15 ], and as additive building blocks for polymer composites [ 16 ].…”

Fullerene-MWCNT nanostructured-based electrochemical sensor for the detection of Vanillin as food additive

“…Several analytical techniques have been proposed for the quantitative determination of VAN such as high performance liquid chromatography with a fluorescence detector (Nasuno, et al, 2020), capillary electrophoresis (Shu et al, 2016), optical fluorescence (Dur an & Contento, 2015) and J o u r n a l P r e -p r o o f colorimetric assay (Zhao et al, 2018). However, these techniques are often complicated, expensive, require qualified personnel and often very long analysis time.…”

Voltammetric Determination of Vanillin Using a Pretreated Pencil Graphite Electrode

“…In the determination of vanillin a variety of methods have been developed using chromatographic [5][6][7][8], spectroscopic [3,9,10] and electroanalytical techniques [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. Although chromatographic methods such as GC and HPLC with various detectors (especially MS detector) have been widely used for the selective and reliable detection of vanillin [5][6][7][8], they have some drawbacks such as time consuming sample pretreatment procedures, high cost, expensive devices, high consumption of organic solvent, needs highly trained personal etc.…”