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Simultaneous detection of 12 mycotoxins in cereals using RP-HPLC-PDA-FLD with PHRED and a post-column derivatization system

Soleimany F, Jinap S, Rahmani A, Khatib A

Food Addit Contam Part A Chem Anal Control Expo Risk Assess, 2011 Apr;28(4):494-501.
PMID: 21337232 DOI: 10.1080/19440049.2010.551547

A new method for the simultaneous quantification of 12 mycotoxins was developed and optimized using reverse phase high performance liquid chromatography (RP-HPLC) with a photodiode array (PDA) and fluorescence detector (FLD), a photochemical reactor for enhanced detection (PHRED) and post-column derivatization. The mycotoxins included aflatoxins (AFB(1), AFB(2), AFG(1), and AFG(2)), ochratoxin A (OTA), zearalenone (ZEA), deoxynivalenol (DON), fumonisins (FB(1), FB(2), and FB(3)), T-2 and HT-2 toxins. A double sample extraction with a phosphate-buffered saline solution (PBS) and methanol was used for co-extraction of mycotoxins, and a multifunctional immunoaffinity column was used for cleanup. Optimum conditions for separation of the mycotoxins were obtained to separate 12 mycotoxins in FLD and PDA chromatograms with a high resolution. The method gave recoveries in the range 72-111% when applied to spiked corn samples. The limits of detection (LOD) were 0.025 ng/g for AFB(1) and AFG(1), 0.012 ng/g for AFB(2) and AFG(2), 0.2 ng/g for OTA, 1.5 ng/g for ZEA, 6.2 ng/g for FB(1), FB(3) and HT-2 toxin, 9.4 ng/g for FB(2) and T-2 toxin, and 18.7 ng/g for DON. In addition, the limits of quantification (LOQ) ranged from 0.04 ng/g for AFB(2) and AFG(2) to 62 ng/g for DON. The method was successfully applied to the determination of these mycotoxins in 45 cereal samples obtained from the Malaysian market. The results indicated that the method can be applied for the multi-mycotoxin determination of cereals.
Validation of the procedure for the simultaneous determination of aflatoxins ochratoxin A and zearalenone in cereals using HPLC-FLD

Rahmani A, Jinap S, Soleimany F

Food Addit Contam Part A Chem Anal Control Expo Risk Assess, 2010 Dec;27(12):1683-93.
PMID: 20960359 DOI: 10.1080/19440049.2010.514951

Method validation for quantitative analysis of aflatoxins (AFs), ochratoxin A (OTA) and zearalenone (ZEA) in cereals using HPLC with fluorescence detector (FLD) is described. Mycotoxins were extracted with methanol : water (80 : 20) and purified with a multifunctional AOZ immunoaffinity column before HPLC analysis. The validation of the analytical method was performed to establish the following parameters: specificity, selectivity, linearity, limits of detection (LOD) and quantification (LOQ), accuracy, precision (within- and between-day variability), stability, robustness, measurement of performance, and measurement of uncertainty. Calibration curves were linear (r > 0.999) over the concentration range, from the LOQ to 26, 40 and 400 ng/g for AFs, OTA and ZEA, respectively. LOD and LOQ were 0.0125 and 0.05 ng/g for aflatoxin B1 (AFB1) and G1 (AFG1), 0.0037 and 0.015 ng/g for aflatoxin B2 (AFB2) and G2 (AFG2), as well as 0.05 and 0.2 ng/g for OTA and 0.5 and 2 ng/g for ZEA, respectively. The mean recovery values were 77-104% for different concentrations of AFs, OTA and ZEA in spiked cereal samples. Both intra- and inter-day accuracy and precision were within acceptable limits. This method was successfully applied for the simultaneous determination of mycotoxins for 60 cereal samples collected from Malaysian markets. Fifty per cent of the cereal samples were contaminated with at least one of these mycotoxins, at a level greater than the LOD. Only one wheat sample and two rice samples were contaminated with levels greater than the European Union regulatory limits for AFs and OTA (4 and 5 ng/g). The means and ranges of mycotoxins obtained for the cereal samples were 0.4 ng/g and 0.01-5.9 ng/g for total AFs; 0.18 ng/g and 0.03-5.3 ng/g for OTA; and 2.8 ng/g and 2.4-73.1 ng/g for ZEA, respectively. The results indicate that the method is suitable for the simultaneous determination of AFs, OTA and ZEA in cereals and is suitable for routine analysis.
Qualitative and Quantitative Analysis of Mycotoxins

Rahmani A, Jinap S, Soleimany F

Compr Rev Food Sci Food Saf, 2009 Jul;8(3):202-251.
PMID: 33467794 DOI: 10.1111/j.1541-4337.2009.00079.x

Mycotoxin toxicity occurs at very low concentrations, therefore sensitive and reliable methods for their detection are required. Consequently, sampling and analysis of mycotoxins is of critical importance because failure to achieve a suitable verified analysis can lead to unacceptable consignments being accepted or satisfactory shipments unnecessarily rejected. The general mycotoxin analyses carried out in laboratories are still based on physicochemical methods, which are continually improved. Further research in mycotoxin analysis has been established in such techniques as screening methods with TLC, GC, HPLC, and LC-MS. In some areas of mycotoxin method development, immunoaffinity columns and multifunctional columns are good choices as cleanup methods. They are appropriate to displace conventional liquid-liquid partitioning or column chromatography cleanup. On the other hand, the need for rapid yes/no decisions for exported or imported products has led to a number of new screening methods, mainly, rapid and easy-to-use test kits based on immuno-analytical principles. In view of the fact that analytical methods for detecting mycotoxins have become more prevalent, sensitive, and specific, surveillance of foods for mycotoxin contamination has become more commonplace. Reliability of methods and well-defined performance characteristics are essential for method validation. This article covers some of the latest activities and progress in qualitative and quantitative mycotoxin analysis.
Optimization and validation of a HPLC method for simultaneous determination of aflatoxin B1, B2, G1, G2, ochratoxin A and zearalenone using an experimental design

Rahmani A, Selamat J, Soleimany F

Food Addit Contam Part A Chem Anal Control Expo Risk Assess, 2011;28(7):902-12.
PMID: 21598138 DOI: 10.1080/19440049.2011.576436

A reversed-phase HPLC optimization strategy is presented for investigating the separation and retention behavior of aflatoxin B1, B2, G1, G2, ochratoxin A and zearalenone, simultaneously. A fractional factorial design (FFD) was used to screen the significance effect of seven independent variables on chromatographic responses. The independent variables used were: (X1) column oven temperature (20-40°C), (X2) flow rate (0.8-1.2 ml/min), (X3) acid concentration in aqueous phase (0-2%), (X4) organic solvent percentage at the beginning (40-50%), and (X5) at the end (50-60%) of the gradient mobile phase, as well as (X6) ratio of methanol/acetonitrile at the beginning (1-4) and (X7) at the end (0-1) of gradient mobile phase. Responses of chromatographic analysis were resolution of mycotoxin peaks and HPLC run time. A central composite design (CCD) using response surface methodology (RSM) was then carried out for optimization of the most significant factors by multiple regression models for response variables. The proposed optimal method using 40°C oven temperature, 1 ml/min flow rate, 0.1% acetic acid concentration in aqueous phase, 41% organic phase (beginning), 60% organic phase (end), 1.92 ratio of methanol to acetonitrile (beginning) and 0.2 ratio (end) for X1-X7, respectively, showed good prediction ability between the experimental data and predictive values throughout the studied parameter space. Finally, the optimized method was validated by measuring the linearity, sensitivity, accuracy and precision parameters, and has been applied successfully to the analysis of spiked cereal samples.
Fulltext Prevalence of the rs7903146C>T polymorphism in TCF7L2 gene for prediction of type 2 diabetes risk among Iranians of different ethnicities

Allahdini M, Kamalidehghan B, Akbari L, Azadfar P, Rahmani A, Ahmadipour F, et al.

Drug Des Devel Ther, 2015;9:5835-41.
PMID: 26604685 DOI: 10.2147/DDDT.S82485

Pharmacogenetics is the study of genetic polymorphisms affecting responses to drug therapy. The common rs7903146 (C>T) polymorphism of the TCF7L2 gene has recently been associated with type 2 diabetes (T2D). In this study, prevalence of the rs7903146 (C>T) polymorphism in the TCF7L2 gene for prediction of T2D risk was examined in an Iranian population of different ethnicities.
Fulltext The effect of exercise on balance in patients with stroke, Parkinson, and multiple sclerosis: a systematic review and meta-analysis of clinical trials

Salari N, Hayati A, Kazeminia M, Rahmani A, Mohammadi M, Fatahian R, et al.

Neurol Sci, 2022 Jan;43(1):167-185.
PMID: 34709478 DOI: 10.1007/s10072-021-05689-y

BACKGROUND: Stroke, Parkinson, and multiple sclerosis are a range of diseases affecting the nervous system and show balance impairments due to damage of the balance control system. Many early articles have been published on the effect of exercise on balance in patients suffering from neuromuscular diseases. However, a comprehensive study showing a clear result of these three diseases was not found. Hence, the purpose of the present meta-analysis and systematic review is to determine the effect of exercise on balance in people with stroke, Parkinson, and multiple sclerosis.
METHODS: According to the PRISMA 2009 multi-step instructions, keywords related to the purpose of the research were browsed in the MeSH browser databases; IranDoc, MagIran, IranMedex, SID, ScienceDirect, Web of Science (WoS), ProQuest, Medline (PubMed), Scopus, and Google Scholar were searched to extract articles published in Persian and English language. The search process for retrieving the articles in the sources mentioned from January 01, 2000, to December 30, 2020, was done. The heterogeneity index of the studies was determined using the I2 test. Given the heterogeneity, the random-effects model was used to combine the articles and the results.
RESULTS: Initially, 7067 articles were found, but after removing duplicate and irrelevant articles, 96 clinical trials with a sample size of the intervention group of 1760 people were included in the study. As a result of the articles' composition, the mean balance score index after exercise in the intervention group showed a significant increase of 0.67 ± 0.12 of the unit (P˂0.01). The highest rate of increase in the balance score after the intervention was reported in patients with myelomeningocele with 1.66 ± 0.3 unit (P˂0.01).
CONCLUSION: Considering the positive effect of using exercise on increasing the balance in patients with stroke, Parkinson, and multiple sclerosis, it is recommended that health care providers implement a regular exercise program to improve the condition of these patients.