Wanjun Long,Gaoqiong Deng,Yanmei Zhu,Qingyang Han,Hengye Chen,Yuanbin She,Haiyan Fu
Saffron is a candidate for various kinds of fraud to make huge profits. The present study proposed an efficient three-dimensional (3D) fluorescence sensing strategy based on hydrophilic hydrazine-naphthalimide functionalized chitosan (HN-chitosan) polymer probe for rapid identification and quantification of potential adulteration in saffron. The amino functional group in the HN-chitosan probe reacted specifically with the Oxygen-containing group of active ingredients in saffron, amplifying the signal difference between saffron and the adulterants, which was comprehensively characterized by 3D fluorescence. Four advanced chemometrics methods were applied for the classification of saffron and adulterated saffron, and good performance were obtained in both training and prediction sets. Furthermore, the PLS regression model was applied to the prediction of adulteration level in saffron and showed satisfactory accuracy. This strategy provides a new solution for rapid identification and quantification of potential adulteration in saffron, which contributes to the healthy development of its industry.
Herein, a multi-use strategy was initiated for visual point-of-care tests, adulteration identification, removal and recycling of dyes in both environmental and food samples using hydrophobic deep-eutectic solvent (HDES)-coated paper as an all-in-one device. HDES, which composed by decylic acid and tetraoctylammonium bromide, was prepared as a sorbent for dyes, then paper devices were facilely fabricated by coating HDES onto printing papers. Due to the coexistence of carbon chains, carboxyl and quaternary ammonium groups, HDES-mediated dyes extraction was of fine versatility through electrostatic interaction and hydrophobic effect, by which the recycling rate of dyes reached 96.5 % at only 5 min of extraction time. Colorimetry of dyes in simulated dye effluents and drinks could be ended as fast as 10 s with LODs at 10 −3 mg/mL level, and the colorimetric results were highly agreed with those generated by instrumental techniques and smartphone-based image analysis. Identifications of fruit/vegetable juices and chili oil adulterated with the same-color artificial dyes were also realized in a single paper strip, giving an identification capacity low as to 1.5 × 10 −3 mg/mL. The success of these cases enlightens a new direction for HDES-based multi-purpose application.
In general, fluorescent probes are used to determine certain metal ions due to their high selectivity, whereas the weakly selective probe could produce different fluorescence spectra after interacting with numerous metal ions. Based on the different species and contents of metal ions in rice, the weakly selective fluorescence probe combined with chemometrics for rice origin traceability and adulteration identification was studied in this study. Excitation-emission matrix spectra (EEMs) of rice extracts from different geographical origins (including adulterated rice) combined with the weakly selective probe were collected. Considering the three-dimensional (3D) characteristics of the EEMs, multi-dimensional principal component analysis (M-PCA) and unfold partial least squares discriminant analysis (U-PLS-DA) pattern recognition methods were used to extract useful information from complex 3D fluorescence data. And the models were built to classify the origin and adulteration of rice. The results of the M-PCA analysis showed that rice from different origins could not be completely distinguished from each other, but there was a clustering trend. It was suggested that the 3D fluorescence data measured after the reaction of the weakly selective probe with rice extracts may be used for rice origin traceability combined with pattern recognition. The analysis of 3D fluorescence data based on U-PLS-DA showed that the classification accuracy of training sets was 100%, and the accuracy of predicted sets was 98%. The results of the M-PCA analysis also showed that rice with different adulteration ratios had a clustering trend. The accurate recognition rate of training sets and predicted sets after U-PLS-DA analysis of adulterated rice was 99% and 95%, respectively. The results showed that the weakly selective probe could be used for rice origin traceability and adulteration identification after the reaction with rice extracts, combined with pattern recognition methods. This study broadens the application range of the fluorescent probe, which can be used for origin traceability and adulteration recognition of foods that cannot produce fluorescence themselves.
危险品化学品经营许可证（带存储）