FT-IR Spectroscopy for the Detection of Diethylene Glycol (DEG) Contaminant in Glycerin-Based Pharmaceutical Products and Food Supplements

Hammoudeh, Ayman; Obeidat, Safwan M.; Abboushi, Eman Kh; Mahmoud, Amal

doi:10.17344/acsi.2019.5553

Cited by 10 publications

(4 citation statements)

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“…Furthermore, it is possible to identify spectral features that are characteristic of glycerol, present in the formulation, in the region between 1200 and 900 cm −1 . Specifically, the signals at about 1039 and 1116 cm −1 are attributable to the C-O stretching vibration of the primary and secondary alcohol group, while the band at about 928 cm −1 and the small shoulder at 995 cm −1 are due to the C-H vibrations [50,51]. After ageing, the bands attributed to glycerol are still present; nevertheless, it is possible to observe an increase in the intensities of the absorptions between 2700 and 3600 cm −1 , and changes in band intensities ratios at lower wavenumbers (890 and 1200 cm −1 range), due to the curing of the protective layer and the evaporation of the glycerol [52,53].…”

Section: Coating Applicationmentioning

confidence: 97%

A New Green Coating for the Protection of Frescoes: From the Synthesis to the Performances Evaluation

et al. 2023

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This work presents the formulation and characterization of a new product for the protection of outdoor frescoes from aggressive environmental agents. The formulation is designed as an innovative green coating, prepared through a zero-waste one-pot-synthetic method to form silver nanoparticles (AgNPs) directly in a chitosan-based medium. The AgNPs are seeded and grown in a mixed hydrogel of chitosan, azelaic, and lactic acid, by the reduction of silver nitrate, and using calcium hydroxide as precipitating agent. The rheological properties of this coating base are optimized by the addition of a solvent mixture of glycerol and ethanol with a 1:1 volume ratio. The new formulation and two commercial products (Paraloid® B72 and Proconsol®) are then applied by brush to ad hoc mock-ups to be evaluated for chemical stability, color and gloss variations, morphological variation, hydrophobicity, and water vapor permeability via Fourier-transform infrared spectroscopy (FT-IR) in attenuated total reflection (ATR) mode, spectrophotometer analysis, stereomicroscope observations, UNI EN 15802, and UNI EN 15803, respectively. The results show that the application of the hybrid chitosan-AgNPs coating is promising for the protection of outdoor frescoes and that it can underpin the development of new products that address the lack of conservation strategies specifically designed for wall painting.

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Section: Coating Applicationmentioning

confidence: 97%

A New Green Coating for the Protection of Frescoes: From the Synthesis to the Performances Evaluation

et al. 2023

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“…Moreover, at 1031 and 1110 cm −1 there is the C−O stretching vibration of primary (C 1 −O) and secondary (C 2 −O) alcohol, respectively. 53,54 All of these peaks, however, are overshadowed by the C−O and C−O−C vibrations of PBS in this region, mainly due to the low molar ratio of glycerol with respect to the polymer. And yet, another characteristic peak of glycerol's hydroxyl groups is located at 921 cm −1 and corresponds to C−OH bending, 54 which was stable during its incorporation in the polymer melt (Figure 5b), meaning also no reactions occurred between them; similarly to epoxy-based ones, the mixtures were completely soluble to chloroform.…”

Section: Atr-ftir Analysis Of Pre-cross-linked and Cross-linked Pbs S...mentioning

confidence: 99%

Recycling/Upcycling of Physically Aged Poly(butylene succinate) into PBS Vitrimers through Zn(II)-Catalyzed Melt Vitrimerization

Panagiotopoulos,

Kapageridou,

Karamitrou

et al. 2024

Macromolecules

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Biobased and/or potentially biodegradable polymers have penetrated the market over the last years as sustainable alternatives to their fossil-based equivalents, driven by the community's increasing sensitivity to environmental issues. Nonetheless, replacing fossil-based polymers with bio-ones will not just resolve all problems, and sustainable recycling/upcycling approaches should already be explored. The current work proposes vitrimerization as an alternative route for upcycling low molecular weight polyesters that may derive from end-of-life waste, (chemical) recycling residues, or hydrolyzed in intense storage conditions. Utilizing a hydrolyzed model polyester, poly(butylene succinate) (PBS), two sets of semi-crystalline PBS vitrimers were prepared, cross-linked by either diglycidyl ether of bisphenol A (DGEBA) or glycerol in the presence of Zn(II) transesterification catalyst. By tuning the cross−linker type and loading (0−10% mol with respect to PBS repeating unit), tailor−made cross−linked materials were prepared with high insolubility (gel fraction up to 92%) and lower swelling (up to 900%) compared to conventionally cross−linked PBS, as well as enhanced melt strength (4 orders of magnitude increase in complex viscosity). The characteristic vitrimer behavior was established by oscillatory frequency sweep experiments (up to 10,000% increase of storage modulus at 120 °C) and rapid stress relaxation (e.g., 54−243 s at 160 °C). Interestingly, the reaction temperature was found to only influence the cross-link density attained, while the molar ratio of Zn(II) and actual cross-links dominated the ability for network rearrangement. In addition, the as-prepared vitrimers exhibited improved thermal properties and stability compared to the aged polymer, while they were reprocessed three times by compression molding without significant loss of cross-link density or mechanical performance (tensile strength, Young's modulus).

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“…There was no significant difference in the FTIR spectrum of the eutectic solvent after being mixed with CPO. The peak was obtained at 3355 cm −1 stretching vibration of the O-H group, 2937 cm −1 asymmetric stretching vibration of the CH 2 group, 2875 cm −1 symmetric stretching vibration of the CH 2 group, 1118 cm −1 stretching vibration of the CO group, and 1045 cm −1 asymmetric vibration of the COC group [26][27][28].…”

Section: Conductivity Conductivity Was Related To Viscositymentioning

confidence: 99%

“…The FTIR spectrum of ZnCl 2 obtained produced peaks at wave numbers 3565 cm −1 for the stretching vibration of the O-H group, 1618 cm −1 for the bending vibration of the H-O-H group, and 519 cm −1 for the vibration of the Zn-Cl group [25]. In comparison, the DEG spectrum obtained showed a peak at 3339 cm −1 stretching vibration of the O-H group, 2924 cm −1 asymmetric stretching vibration of the CH 2 group, 2869 cm −1 symmetric stretching vibration of the CH 2 group, 1125 cm −1 stretching vibration of the COC group, and 1052 cm −1 asymmetric vibration of the COC group [26][27][28].…”

Section: Conductivity Conductivity Was Related To Viscositymentioning

confidence: 99%

Reducing Free Fatty Acids in Crude Palm Oil Using Diethylene Glycol and Zinc(II) Chloride Based Deep Eutectic Solvent

Suriyanti,

Usman,

Rahmalia

2024

Indones. J. Chem.

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Deep eutectic solvents (DES) were prepared by precise combinations of mol fractions of chemical compounds, resulting in a lowered melting point due to hydrogen bonding. This research aimed to elucidate the physicochemical attributes of DES and its effectiveness in mitigating free fatty acid (FFA) levels in crude palm oil (CPO). Zinc(II) chloride (ZnCl2) served as the hydrogen bond acceptor (HBA) while diethylene glycol (DEG) as the hydrogen bond donor (HBD). Characterization included freezing point, density, viscosity, conductivity, and pH determination. At a ZnCl2 mol fraction of 0.30, the resulting DES exhibited homogeneity with transparent liquid properties, featuring a freezing point below −10 °C, density of 1.42 g/mL, viscosity of 1933.40 cP, conductivity of 66.13 µS/cm, and pH 3.42. FTIR spectra confirmed hydrogen bond interactions between HBA and HBD. Applied to CPO at a 1:1 volumetric ratio (DES:CPO), with 2 h of stirring time at 50 °C, FFA content decreased from 4.11 to 0.86%. This research highlights DES as an environmentally sustainable purification agent, significantly reducing FFA levels in unrefined palm oil.

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FT-IR Spectroscopy for the Detection of Diethylene Glycol (DEG) Contaminant in Glycerin-Based Pharmaceutical Products and Food Supplements

Cited by 10 publications

References 0 publications

A New Green Coating for the Protection of Frescoes: From the Synthesis to the Performances Evaluation

A New Green Coating for the Protection of Frescoes: From the Synthesis to the Performances Evaluation

Recycling/Upcycling of Physically Aged Poly(butylene succinate) into PBS Vitrimers through Zn(II)-Catalyzed Melt Vitrimerization

Reducing Free Fatty Acids in Crude Palm Oil Using Diethylene Glycol and Zinc(II) Chloride Based Deep Eutectic Solvent

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