Could Infrared Spectroscopy Identify Melamine‐Related Stone Using Melamine‐Contained Mixture as A Reference?

Cong, Xiaoming; Sun, Xu; Ning, Benxiang

doi:10.1002/jcla.21562

Cited by 8 publications

(9 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example, observation of crystalline melamine mid-infrared (MIR) spectral features in admixtures with cyanuric or uric acid depended upon the sample preparation method. 22 Cong et al reported that fingerprint MIR melamine bands (e.g., 6802 and 6944 nm) detected in dry-blended powder admixtures were absent in solid samples prepared by precipitation. Changes in melamine hydrogen bonding (H bonding) alter its vibrational band structure.…”

Section: ■ Introductionmentioning

confidence: 99%

“…However, because NIR screening methods do not use sample cleanup or chromatographic steps, they are more susceptible to matrix interferences. For example, observation of crystalline melamine mid-infrared (MIR) spectral features in admixtures with cyanuric or uric acid depended upon the sample preparation method . Cong et al reported that fingerprint MIR melamine bands (e.g., 6802 and 6944 nm) detected in dry-blended powder admixtures were absent in solid samples prepared by precipitation.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effects of the Adulteration Technique on the Near-Infrared Detection of Melamine in Milk Powder

Scholl

Bergana

Yakes

et al. 2017

J. Agric. Food Chem.

View full text Add to dashboard Cite

The United States Pharmacopeial Convention has led an international collaborative project to develop a toolbox of screening methods and reference standards for the detection of milk powder adulteration. During the development of adulterated milk powder reference standards, blending methods used to combine melamine and milk had unanticipated strong effects on the near-infrared (NIR) spectrum of melamine. The prominent absorbance band at 1468 nm of melamine was retained when it was dry-blended with skim milk powder but disappeared in wet-blended mixtures, where spray-dried milk powder samples were prepared from solution. Analyses using polarized light microscopy, Raman spectroscopy, dielectric relaxation spectroscopy, X-ray diffraction, and mass spectrometry indicated that wet blending promoted reversible and early Maillard reactions with lactose that are responsible for differences in melamine NIR spectra between wet- and dry-blended samples. Targeted detection estimates based solely on dry-blended reference standards are likely to overestimate NIR detection capabilities in wet-blended samples as a result of previously overlooked matrix effects arising from changes in melamine hydrogen-bonding status, covalent complexation with lactose, and the lower but more homogeneous melamine local concentration distribution produced in wet-blended samples. Techniques used to incorporate potential adulterants can determine the suitability of milk reference standards for use with rapid detection methods.

show abstract

Section: ■ Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effects of the Adulteration Technique on the Near-Infrared Detection of Melamine in Milk Powder

Scholl

Bergana

Yakes

et al. 2017

J. Agric. Food Chem.

View full text Add to dashboard Cite

show abstract

“…Later, this contamination was found to cause a series of food safety incidents . Of these incidents, the most serious was the formation of urinary stones in infants ingesting MEL-contaminated formula. − Analysis of the stones showed that they are composed of MEL and UA (Chart ) in nearly equimolar amounts − and suggested that 1:1 H-bonded interaction of the two components may be responsible for the stone formation. , …”

Section: Introductionmentioning

confidence: 99%

Multiple Hydrogen-Bonding Interactions of Uric Acid/9-Methyluric Acid with Melamine Identified by Infrared Spectroscopy

Asami

Saigusa

2014

J. Phys. Chem. B

View full text Add to dashboard Cite

Hydrogen-bonded complexes of uric acid/9-methyluric acid (UA/9MUA) with melamine (MEL) are prepared by the combined technique of laser desorption and supersonic-jet expansion, and their stable structures are investigated by infrared spectroscopy and theoretical calculations. It is shown that the 1:1 complex formed between UA and MEL is of nonplanar type, in which the two chromophore planes are significantly folded and thus allow for triple hydrogen-bonding interactions. An anomalously broad IR band is observed in the low-frequency range 2500-2800 cm(-1), which is taken as evidence for the formation of a strong hydrogen bond between one of the NH sites of UA and MEL. In the case of 9MUA, in which hydrogen bonding to the N9H site of UA is blocked by the methyl group, two planar pairs formed of 9MUA and MEL are found to coexist. The nature of the multiple hydrogen-bonding interactions in these complexes is discussed based on the natural bond orbital analysis and compared with those of the guanine-cytosine base pair. The results are expected to provide important information on the structural characterization of urinary stones developed in infants after ingesting MEL-contaminated formula.

show abstract

“…Bands typically seen in melamine at 5115, 4860, and 4713 cm –1 were shifted in the WB-Lac to lower positions or weakened in intensity (i.e., 5084, 4821, and 4706 vw cm –1 ). Other model systems have reported the disappearance of the sharp, fundamental NH 2 stretching vibration near 3470 and 3420 cm –1 in the MIR spectrum in samples containing melamine H bonding with uric or cyanuric acid. This is consistent with the disappearance of the primary melamine NH 2 first overtone band at 6812 cm –1 in this NIR work, which led to the conclusion that lactose may have formed a similar H bond with melamine during the production of wet-blended samples.…”

Section: Resultsmentioning

confidence: 96%

Effects of Wet-Blending on Detection of Melamine in Spray-Dried Lactose

Yakes

Bergana

Scholl

et al. 2017

J. Agric. Food Chem.

View full text Add to dashboard Cite

During the development of rapid screening methods to detect economic adulteration, spray-dried milk powders prepared by dissolving melamine in liquid milk exhibited an unexpected loss of characteristic melamine features in the near-infrared (NIR) and Raman spectra. To further characterize this "wet-blending" phenomenon, spray-dried melamine and lactose samples were produced as a simplified model and investigated by NIR spectroscopy, Raman spectroscopy, proton nuclear magnetic resonance (H NMR), and direct analysis in real time Fourier transform mass spectrometry (DART-FTMS). In contrast to dry-blended samples, characteristic melamine bands in NIR and Raman spectra disappeared or shifted in wet-blended lactose-melamine samples. Subtle shifts in melamine H NMR spectra between wet- and dry-blended samples indicated differences in melamine hydrogen-bonding status. Qualitative DART-FTMS analysis of powders detected a greater relative abundance of lactose-melamine condensation product ions in the wet-blended samples, which supported a hypothesis that wet-blending facilitates early Maillard reactions in spray-dried samples. Collectively, these data indicated that the formation of weak, H bonded complexes and labile, early Maillard reaction products between lactose and melamine contribute to spectral differences observed between wet- and dry-blended milk powder samples. These results have implications for future evaluations of adulterated powders and emphasize the important role of sample preparation methods on adulterant detection.

show abstract

Could Infrared Spectroscopy Identify Melamine‐Related Stone Using Melamine‐Contained Mixture as A Reference?

Abstract: Our results indicate the identification of melamine-related stone by infrared spectroscopy could not use the infrared spectrum of melamine-contained mixtures as a reference.

Cited by 8 publications

References 10 publications

Effects of the Adulteration Technique on the Near-Infrared Detection of Melamine in Milk Powder

Effects of the Adulteration Technique on the Near-Infrared Detection of Melamine in Milk Powder

Multiple Hydrogen-Bonding Interactions of Uric Acid/9-Methyluric Acid with Melamine Identified by Infrared Spectroscopy

Effects of Wet-Blending on Detection of Melamine in Spray-Dried Lactose

Contact Info

Product

Resources

About