In this study, a HPTLC-platformed SERS detection was established for screening thiram in juice. After a simple extraction, the sample liquid was separated on HPTLC plates, which resulted in a specific zone for the analyte. Following infiltration with atomize water, the band of interest was easily scraped off and eluted. In parallel, a flexible and SERS-active substrate was fabricated by the in-situ synthesis of gold nanoparticles within cotton fabrics. Under optimized conditions, fingerprint-like signal at 1376 cm −1 of the analyte were easily recorded by a hand-held Raman spectrometer with enough LOD (0.5 mg/L), LOQ (0.9 mg/L) and reproducibility (<11.7%). The optimized screening system was further validated with pear, apple and mango juice by determining the spike-and-recovery rates (75.6 to 112.8%). It was demonstrated that this method could be a facile point-of-care testing system tailored for pesticide screening.
Jian Song,Shuyu Lai,Dingnan Wang,Xiaomei Wu,Yiming Zhang,Linjiang Pang,Tingting Chai,Ji Zhao,Xiaodong Wang
The development of simultaneous and rapid screening of the residues of veterinary drugs and their metabolites is up to now still a challenge. In this study, a novel strategy of read-out analysis is proposed based on high-performance thin-layer chromatography (HPTLC) separation coupled with self-visualization detection of trace of leucomalachite Green (LMG) and malachite green (MG) in aquatic products. The novel self-visualization nanomaterial was successfully synthesized and subsequently fully characterized. The ionic associate MG–I 3 formed on the visualization sensing interface was effectively attested by MALDI-TOF/TOF-MS for the first time. A serials of visualization reactions were conducted on the target zone surface of HPTLC after separation. Under the optimum conditions, the calibration curves of LMG and MG were obtained with good linearity in the range of 0.25–8.0 μg mL −1 and 0.125–4.0 μg mL −1 , respectively. The limits of detection and limit of quantification were calculated as 1.71 and 5.19 μg kg −1 for LMG and 0.9 and 2.74 μg kg -1 for MG, respectively. Real sample analysis and validation provided satisfactory results. The proposed method has the potential to detect simultaneously, rapidly, and accurately LMG and MG in aquatic products during storage, handling, and sales.
The global consumption of Citri reticulatae pericarpium (Chenpi, CP) and Citrus reticulata 'chachi' (Guangchenpi, GCP) has been experiencing a steady increase, driven by its extensive applications in healthcare, flavoring, and therapeutic fields. While the two varieties exhibit analogous macroscopic characteristics and therapeutic efficacies, rigorous market differentiation and identification are imperative owing to their distinct botanical origins, qualitative specifications, and especially significant price discrepancy. A comprehensive strategy integrating HPTLC and UHPLC analyses with machine learning was implemented in this research to discriminate between CP and GCP and to conduct a comparative content analysis of three characteristic flavonoids in the two materials. The discrimination results of eight models upon HPTLC data reveal that all models except Tree achieved 100% discrimination accuracy. (2S)-Narirutin, Nobiletin, and Tangeretin, three compounds contributed to the differentiation were quantified and exhibited distinct content differences in CP and GCP samples. This study could provide simple and scientific guidance for the authentication of the two varieties.
危险品化学品经营许可证（带存储）