We propose a very simple and fast method for detecting Sudan dyes (I, II, III and IV) in commercial spices, based on characterizing samples through their UV-visible spectra and using multivariate classification techniques to establish classification rules. We applied three classification techniques: K-Nearest Neighbour (KNN), Soft Independent Modelling of Class Analogy (SIMCA) and Partial Least Squares Discriminant Analysis (PLS-DA). A total of 27 commercial spice samples (turmeric, curry, hot paprika and mild paprika) were analysed by chromatography (HPLC-DAD) to check that they were free of Sudan dyes. These samples were then spiked with Sudan dyes (I, II, III and IV) up to a concentration of 5 mg L(-1). Our final data set consisted of 135 samples distributed in five classes: samples without Sudan dyes, samples spiked with Sudan I, samples spiked with Sudan II, samples spiked with Sudan III and samples spiked with Sudan IV. Classification results were good and satisfactory using the classification techniques mentioned above: 99.3%, 96.3% and 90.4% of correct classification with PLS-DA, KNN and SIMCA, respectively. It should be pointed out that with SIMCA, there are no real classification errors as no samples were assigned to the wrong class: they were just not assigned to any of the pre-defined classes.
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http://dx.doi.org/10.1016/j.talanta.2009.05.023 | DOI Listing |
Anal Methods
November 2017
College of Environmental and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063, China.
A novel method was established using a restricted access material combined with a molecularly imprinted polymer (RAM-MIP) as the sorbent material in solid phase extraction (SPE) for clean-up of α-endosulfan, β-endosulfan, endosulfate, endosulfan-ether, endosulfan lactone, heptachlor, heptachlor--epoxide, and heptachlor--epoxide in pork and gas chromatography (GC) for determination. The RAM-MIP was prepared by precipitation polymerization by using endosulfan as the template, methacrylic acid (MAA) as the monomer, glycidyl methacrylate (GMA) as the pro-hydrophilic co-monomer, ethylene glycol dimethacrylate (EGDMA) as the crosslinker, azobisisobutyronitrile (AIBN) as the initiator, and toluene as the porogen. Ultraviolet spectroscopy (UV) and H-nuclear magnetic resonance (H-NMR) analysis verified that MAA interacted specifically with endosulfan in a ratio of 1 : 1 in the pre-polymerization solution.
View Article and Find Full Text PDFPoult Sci
January 2025
Ancera, Inc, Branford, CT 06405, USA. Electronic address:
Necrotic enteritis (NE), caused by the gram-positive, anaerobic bacterium, Clostridium perfringens, results in an estimated $6 billion in annual economic losses to the global poultry industry. C. perfringens is part of the normal microflora of the poultry gastrointestinal tract, but damage to the intestinal epithelium can lead to increased cell proliferation and production of toxins which gives rise to disease.
View Article and Find Full Text PDFPLoS One
January 2025
Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America.
Tick-borne spotted fever rickettsioses (SFRs) continue to cause severe illness and death in otherwise-healthy individuals due to lack of a timely and reliable diagnostic laboratory test. We recently identified a diagnostic biomarker for SFRs, the putative N-acetylmuramoyl-l-alanine amidase RC0497. Here, we developed a prototype laboratory test that targets RC0497 for diagnosis of SFRs.
View Article and Find Full Text PDFAnal Chem
January 2025
Tianjin Key Laboratory of Food Science and Health, School of Medicine, Nankai University, Tianjin 300071, China.
() is one of the most prevalent threats, capable of inducing diverse illnesses and presenting a serious threat to public health. Herein, we demonstrate a novel dual-mode colorimetric/fluorescence biosensor based on the xponential mplification reaction and trand isplacement eactions (EASDR), which has multiplexing capability that significantly promotes the anchoring and trapping of Pt nanoparticles (Pt NPs) and fluorescent dyes for sensitive detection of (). The method works by targeting specific bacteria with aptamers and promoting repeated EASDR to affect the immobilization of Pt NPs and fluorescent dyes in the orifice plate, which could produce changes in fluorescence and colorimetric signals.
View Article and Find Full Text PDFAnal Chem
January 2025
Department of Biomedical Engineering, Lund University, Lund SE-223 63, Sweden.
Isolation and characterization of circulating tumor cells (CTCs) present a noninvasive alternative to monitor disease progression in individual patients. However, the heterogeneous lineage specificity of CTCs makes it difficult to isolate and identify possible CTCs by a liquid biopsy. Better label-free methods for the isolation of viable CTCs are needed.
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