scholarly journals Single-Laboratory Validation for the Determination of Cocoa Flavanols and Procyanidins (by Degree of Polymerization DP1–7) in Cocoa-Based Products by Hydrophilic Interaction Chromatography Coupled with Fluorescence Detection: First Action 2020.05

Author(s):  
Ugo Bussy ◽  
Gregory Hewitt ◽  
Yusuf Olanrewaju ◽  
Brian R May ◽  
Nicholas Anderson ◽  
...  

Abstract Background Flavanols and procyanidins are complex bioactives found in many foods such as cocoa. As their consumption is associated with health benefits, cocoa flavanols and procyanidins are receiving increasing attention from consumers, industry, researchers, and regulators. Objective The objective of this study is to validate a method using hydrophilic interaction chromatography (HILIC) with fluorescence detection (FLD) and a commercially available reference material for the determination of flavanols and procyanidins (CF) in cocoa-based products. Methods Method performances were evaluated for cocoa matrices with CF content that ranged from 0.8 to 500 mg/g, which included low CF matrices (milk and dark chocolate, cocoa powder, and liquor) and high CF matrices (cocoa extract and dietary supplement products). The method was validated in a single-laboratory by determining sensitivity, selectivity, linearity, stability, robustness, accuracy, and precision for each of the matrices. Results The method was validated for cocoa matrices with CF content that ranged from 0.8 to 500 mg/g. Accuracy ranged from 86 to 99% and repeatability (RSDr) from 1.5 to 8.6% for CF. Conclusions Analytical performances acquired through this single-laboratory validation study for a wide range of cocoa-based matrices demonstrate that this method is fit-for-purpose for the determination of flavanols and procyanidins in cocoa-based products. Highlights Hydrophilic interaction chromatography (HILIC) with fluorescence detection was successfully used to determine total CF content in multiple product types. Single-laboratory method validation results demonstrate that the method is fit for purpose for cocoa-based matrices containing <0.8 to 500 mg/g of CF.

2014 ◽  
Vol 97 (1) ◽  
pp. 166-172 ◽  
Author(s):  
Philip R Machonis ◽  
Matthew A Jones ◽  
Catherine Kwik-Uribe

Abstract Recently, a multilaboratory validation (MLV) of AOAC Official Method 2012.24 for the determination of cocoa flavanols and procyanidins (CF-CP) in cocoa-based ingredients and products determinedthat the method was robust, reliable, and transferrable. Due to the complexity of the CF-CP molecules, this method required a run time exceeding 1 h to achieve acceptable separations. To address this issue, a rapid resolution normal phase LC method was developed, and a single-laboratory validation (SLV) study conducted. Flavanols and procyanidins with a degree of polymerization (DP) up to 10 were eluted in 15 min using a binary gradient applied to a diol stationary phase, detected using fluorescence detection, and reported as a totalsum of DP 1–10. Quantification was achieved using (-)-epicatechin-based relative response factors for DP 2–10. Spike recovery samplesand seven different types of cocoa-based samples were analyzed to evaluate the accuracy, precision, LOD, LOQ, and linearity of the method. The within-day precision of the reported content for the samples was 1.15–5.08%, and overall precision was 3.97–13.61%. Spike-recovery experiments demonstrated recoveries of over 98%. The results of this SLV were compared to those previously obtained in the MLV and found to be consistent. The translation to rapid resolution LC allowed for an 80% reduction in analysis time and solventusage, while retaining the accuracy and reliability of the original method. The savings in both cost and time of this rapid method make it well-suited for routine laboratory use.


2019 ◽  
Vol 102 (6) ◽  
pp. 1666-1672
Author(s):  
Manisha Dhanshetty ◽  
Kaushik Banerjee

Background: Mycotoxins such as aflatoxins (AFs) and ochratoxin A (OTA) can pose severe health hazards because of their toxicity. Given a wide range of food matrices susceptible to fungal infections and possible cooccurrence of mycotoxins at different concentrations, validated multimycotoxin and multimatrix methods are strongly warranted. Objective: The aim of this research was to develop a simple and fast ultra-high performance LC (UHPLC) fluorescence detection (FLD)–based method to simultaneously determine AFs (B1, G1, B2, and G2) and OTA and, furthermore, to carry out single-laboratory validation in a range of cereals and processed product matrices. Methods: The sample preparation involved homogenization and extraction with methanol–water (80 + 20). For cleanup, an aliquot (3 mL) was diluted with phosphate-buffered saline, loaded on an immunoaffinity column (AFLAOCHRA PREP®), and eluted with methanol (1 mL). The cleaned extract was diluted with 0.2% acetic acid (at a 1:1 ratio) before injection into an ultra-high performance liquid chromatograph. To perform simultaneous analysis of AFs and OTA, the FLD program was developed by switching the excitation wavelength in a single chromatographic run. Results: The method provided LOQs of 0.25 and 1 ng/g for AFs and OTA, respectively, without involving any derivatization. In rice, the recoveries of AFs ranged from 84 to 106%, whereas OTA had a recovery above 72%, with the repeatability relative SDs <12% for both analytes. The method was successfully applied to a range of naturally contaminated market samples. Conclusions: The method is suitable for regulatory testing because of its significant time and cost effectiveness and sensitivity in compliance with the regulatory maximum levels. Highlights: The study achieves high-throughput analysis of AFs and OTA in raw and processed cereals using simultaneous extraction, cleanup, and UHPLC-FLD. Method sensitivity complies with the regulatory maximum levels. Single-laboratory validation results meet analytical QC requirements.


2020 ◽  
Vol 12 (28) ◽  
pp. 3592-3599
Author(s):  
Chen Wang ◽  
Hongping Chen ◽  
Li Zhu ◽  
Xin Liu ◽  
Chengyin Lu

An accurate, sensitive and rapid method for determination of perchlorate in tea by hydrophilic interaction chromatography-tandem mass spectrometry.


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