UV-Vis Spectroscopy of Carbohydrates

"To quantify the glycuronic acid content, a modified m-hydroxybiphenyl technique was utilized, with galacturonic acid serving as the standard, employing galacturonic acid as the standard, and absorbance was recorded at 520 nm." — Uronic acid (glycuronic acid) colorimetric assay. [Zhang S, Liu T, Qu X, Zhang W, Wu X, Liu Y, Li S, Shi D, Li H, Gong A, 2026, <i>Inonotus obliquus</i> Polysaccharides Prevent High-Fat Diet-Induced Obesity in Mice Related to Reshaping Gut Microbiota.; confidence: high]

"This derivative reacts with anthrone to form a blue-green complex, with a maximum absorption wavelength of 620 nm." — Review of polysaccharide detection methods; anthrone-sulfuric acid read at 620 nm. [Zhang L, Wang X, Zhang J, Liu D, Bai G, 2026, Research progress of polysaccharide detection methods in traditional Chinese medicine.; confidence: high]

"The concentration of total polysaccharides was evaluated via an adapted phenol-sulfuric acid colorimetric approach, employing glucose as the reference standard and absorbance was measured at 490 nm." — Standard detection wavelength for the phenol-sulfuric acid total-carbohydrate assay. [Zhang S, Liu T, Qu X, Zhang W, Wu X, Liu Y, Li S, Shi D, Li H, Gong A, 2026, <i>Inonotus obliquus</i> Polysaccharides Prevent High-Fat Diet-Induced Obesity in Mice Related to Reshaping Gut Microbiota.; confidence: high]

"DNS reacts with reducing sugars released from starch hydrolysis; therefore, lower absorbance at 540 nm indicates stronger α-amylase inhibition." — Working wavelength of the DNS reducing-sugar assay (540 nm). [Qayyum A, Junejo SA, Xu Z, Hassan MZ, Liu B, Chen Z, 2026, The Effect of Lactic Acid Bacteria Fermentation on the Anti-Diabetic Activity of Pumpkin Puree; confidence: high]

"UV Spectral Characterization of Polysaccharide Purity The UV (Figure 5) absorption spectrum of EAP in the 200–400 nm range showed a strong terminal absorption at approximately 200 nm, which is characteristic of polysaccharides." — Terminal/end absorption ~200 nm; absence of 260/280 nm peaks indicates low nucleic acid/protein. [Ayideng H, Huang S, Yaermaimaiti B, Nazhaer N, Yasen N, Zeng L, Tayier B, Mulati A, 2026, Extraction, Purification, Structural Characterization, and In Vitro Simulated Digestion of Polysaccharides from <i>Elaeagnus angustifolia</i>.; confidence: high]

"It is noted that the absorption behavior of the mixture is characterized by the presence of an absorption peak at 202 nm, in addition to the presence of a shoulder in the range 280–315 nm." — Peak 202 nm; shoulder 280-315 nm recorded in notes only (not a separate numeric band). Chitosan component contributes the UV absorption. [Elhendawi H, Ramadan RM, Ali AM, Fahmy T, 2026, Fabrication and characterization of eco-friendly PVA/chitosan/TEA-TOS composites as a potential light-absorbing material for energy storage and optoelectronics.; confidence: high]

"As shown in Figure 1a, the TP sample exhibits a strong end absorption of the polysaccharide backbone only near 200 nm within the range of 200–800 nm." — No obvious absorption at 260 nm (nucleic acid) or 280 nm (protein). [Zhou S, Di N, 2026, Preparation of polysaccharides from <i>Trichosanthes kirilowii</i> Maxim. and their antioxidant and hypoglycemic activities.; confidence: high]

"The UV–vis spectrum of BCDs in aqueous dispersion (Fig 2a) exhibits a distinct absorption peak at approximately 275 nm, which is typically attributed to the π–π* transition of aromatic C = C bonds, indicating the presence of conjugated sp² carbon domains." — Value reported as 'approximately 275 nm'; biowaste-derived, used in biodegradable fluorescent films. [Matalqah SM, Singamaneni VR, Jahnavi P, Hani U, Fatima F, Vodeti R, Gupta PS, Duza MB, Amin MA, 2026, Bio-waste derived fluorescent carbon dots based biodegradable mechanically strong hydrogel for stimuli-responsive nonsteroidal anti-inflammatory drug (NSAID) delivery.; confidence: high]