ABSTRACT
INTRODUCTION: Aflatoxins, potent carcinogens produced by Aspergillus species, present significant health risks and commonly contaminate herbal products such as Chrysanthemum morifolium. Detecting these toxins in C. morifolium proves challenging due to the complex nature of the herbal matrix and the fluctuating levels of toxins found in different samples. OBJECTIVES: This study aimed to develop and optimize a novel method for the detection of aflatoxins in C. morifolium using dispersive liquid-liquid microextraction combined with high-performance liquid chromatography-fluorescence detection based on quality by design principles. METHODOLOGY: The method involved determining critical method attributes and parameters through the Plackett-Burman design, followed by optimization using the Box-Behnken design. Monte Carlo simulation was employed to establish a design space, which was experimentally verified. Method validation was performed to confirm accuracy, precision, and stability. RESULTS: The developed method exhibited excellent linearity (R2 > 0.9991) for aflatoxins B1, B2, G1, and G2 across a range of concentrations, with recovery rates between 85.52% and 102.01%. The validated method effectively quantified aflatoxins in C. morifolium under different storage conditions, highlighting the impact of temperature and storage time on aflatoxin production. CONCLUSION: This study successfully established a reliable and effective method for the detection of aflatoxins in C. morifolium, highlighting the importance of strict storage conditions to reduce aflatoxin contamination. Using a quality by design framework, the method demonstrated robustness and high analytical performance, making it suitable for routine quality control of herbal products.
ABSTRACT
The development of HPLC analytical methods for traditional Chinese medicine is intricate and time-consuming, influenced by factors such as column wear, solvent purity, and instrumental settings. A comprehensive evaluation of the HPLC system is crucial to mitigate potential variability and ensure the reliability of data. This is especially important given the complex and synergistic nature of the chemical components in traditional Chinese medicine, necessitating a multivariate measurement system analysis (MSA) to assess multiple correlated quality characteristics effectively. This study introduced a multivariate MSA method based on weighted principal components (WPC) to evaluate the HPLC system for the determination of metabolites in Gastrodia elata. By integrating multiple principal components and assigning weights according to their eigenvalues, the WPC method significantly enhanced both accuracy and robustness. It demonstrated a repeatability and reproducibility (% R&R) of 26.43% and a number of distinct categories (ndc) index of 5, confirming the system's acceptability. A full factorial experimental design was employed to identify key performance factors, leading to the recommendation to use five reference solutions for the standard curve and to triple sample preparations for improved precision and accuracy. Monte Carlo simulations confirmed the reliability of the system, showing % R&R and ndc values that follow a normal distribution, ranging from 19% to 22% and 6.07 to 7.38, respectively. Chromatographic conditions were optimized using a Box-Behnken experimental design. Subsequent validation experiments verified the method's high accuracy and reliability, with all relative standard deviation values for analytical precision, repeatability, and stability below 5%. The method also exhibited high recovery rates, exceeding 91% across three concentration levels, with RSD values under 4%. In conclusion, the application of a WPC-based multivariate MSA enabled a detailed evaluation of the HPLC system, ensuring accurate and reliable measurement of quality attributes. This method exemplified a scientifically rigorous approach for developing analytical methods in traditional Chinese medicine, enhancing both precision and reliability.
ABSTRACT
A method for the determination of four fluorescent whitening agents (FWAs) (FWA 357, FWA 220, FWA 204 and FWA 113) in disposable sanitary products by high performance liquid chromatography with diode array detection (HPLC-DAD) was developed. The sample was extracted with a 20 mL ultrapure water by sonication for 30 min at 80 °C. The HPLC method was performed on an SB Phenyl column (250 mm x 4. 6 mm, 5 µm) by gradient elution using 5 mmol/L ammonium acetate and acetonitrile as mobile phases, which can separate the target analytes successfully. The target analytes showed good linearity in the range of 0. 025-400 mg/L with the correlation coefficients (r2) greater than 0. 999 9. The limits of detection (LODs, S/N =3) were 0.02-0. 1 mg/L, and the method limits of quantification (MLOQs) were 1. 0 - 5. 0 mg/kg for the target analytes. The feasibility of this method was demonstrated by the determination of FWAs in samples with spiked recoveries. The recoveries were in the range between 83. 7% and 101. 0%, and the relative standard deviations (RSDs) (n=6) ranged from 2. 4% to 7. 0%. This method is simple, and has high recoveries for the determination of FWAs in disposable sanitary products.
ABSTRACT
In the present study, the synthesis of hapten for the organophosphorus (OP) pesticide paraoxon-methyl was developed, with a spacer arm (aminocarboxylic acid) attached at the aromatic ring. It was conjugated to bovine serum albumin (BSA) for use as an immunogen and to ovalbumin (OVA) for coating antigen for ELISA testing. Rabbits were immunized with the immunogen and two polyclonal antisera were produced and screened against the coating antigen using competitive indirect enzyme-linked immunosorbent assay (ELISA). For application to textile samples, the influence of several factors such as organic solvent, ionic strength, and pH on the ELISA results were studied. Under optimized conditions, the quantitative working range was 0.012-1.158 microg/mL with a limit of detection (LOD) of 0.005 microg/mL and the IC(50) was 0.115 microg/mL.There was negligible cross reactivity (CR) with other OP pesticides. The recoveries obtained by standard paraoxon-methyl addition to the different textile samples such as cotton, wool and muslin delaine were all from 86.0% to 108.0%. Therefore, the optimized ELISA may become a new convenient and economical analytical tool for monitoring paraoxon-methyl residues in textile samples.