scholarly journals Ultra-high performance liquid chromatographic determination of aflatoxin M1 in urine

2015 ◽  
Vol 8 (4) ◽  
pp. 405-413 ◽  
Author(s):  
S. Mohd Redzwan ◽  
R. Jamaluddin ◽  
A.M. Mohd Sokhini ◽  
A.R. Nurul Aqilah ◽  
A. Zuraini ◽  
...  
Keyword(s):  
Biological Samples ◽  
Analytical Methods ◽  
High Performance ◽  
Limit Of Detection ◽  
Extraction Procedure ◽  
Aflatoxin M1 ◽  
Enzyme Linked Immunosorbent Assay ◽  
Fluorescence Detector ◽  
The Mean

The development of analytical methods to detect aflatoxin B1 (AFB1) in foodstuffs and its metabolites in human biological samples is useful for risk assessment. The latter methodology, i.e. the measurement of AFB1 biomarkers, has become important to assess human aflatoxin exposure. AFB1-lysine adduct, AFB1-DNA adduct and urinary aflatoxin M1 (AFM1) are some of the AFB1 biomarkers that can be measured by several analytical methods, such as enzyme-linked immunosorbent assay, radioimmunoassay, and high performance liquid chromatography (HPLC). HPLC coupled to a fluorescence detector is useful and preferable due to its high degree of sensitivity, but the analysis may take time and consume large amount of solvents. Therefore, the present study extrapolated the HPLC method to ultra-HPLC for the determination of urinary AFM1. After the extraction procedure with an immunoaffinity column, chromatographic separation was done using a high performance 1.8 μm microparticulate C18 column. The mean recovery from urine samples spiked with 0.5, 1.0 and 2.0 ng/ml AFM1 was 84.4±4.0%, with acceptable recovery values, interday (6.0±5.3%) and intraday (2.6±0.6%) coefficients of variation. The retention time was 5.7 min. This method was used to measure urinary AFM1 in 71 subjects, of which 13 had AFM1 levels above the limit of detection (0.018 ng/ml). The mean urinary AFM1 level of the positive samples was 18.8±28.6 pg/ml, ranging from 2.4 to 100.4 pg/ml. As this is one of the few studies investigating the occurrence of aflatoxin biomarkers in human biological samples in Malaysia, a study with a larger sample size is necessary to investigate the magnitude of aflatoxin exposure among the population.

scholarly journals Determination of Aflatoxin M1 in Raw Milk Using an HPLC-FL Method in Comparison with Commercial ELISA Kits—Application in Raw Milk Samples from Various Regions of Greece

2021 ◽  
Vol 8 (3) ◽  
pp. 46
Author(s):  
Martha Maggira ◽  
Maria Ioannidou ◽  
Ioannis Sakaridis ◽  
Georgios Samouris
Keyword(s):  
Limit Of Detection ◽  
Reference Method ◽  
Raw Milk ◽  
Aflatoxin M1 ◽  
Enzyme Linked Immunosorbent Assay ◽  
Fluorescence Detector ◽  
Elisa Kit ◽  
Milk Samples ◽  
Of Greece

The highly toxic Aflatoxin M1 (AFM1) is most often detected in milk using an Enzyme-Linked-Immunosorbent Assay (ELISA) for screening purposes, while High-Performance Liquid Chromatography with Fluorescence Detector (HPLC-FL) is the reference method used for confirmation. The aim of the present study was the comparison between three commercially available ELISA kits and a newly developed HPLC-FL method for the determination of the AFM1 in milk samples. The developed HPLC-FL method was validated for the AFM1 and Aflatoxin M2 (AFM2), determining the accuracy, precision, linearity, decision limit, and detection capability with fairly good results. All three ELISA kits were also validated and showed equally good performance with high recovery rates. Moreover, the Limit Of Detection (LOD) and Limit Of Quantification (LOQ) values were found to be significantly lower than the Maximum Residue Limit (MRL) (50 ng kg−1). After the evaluation of all three commercial kits, the ELISA kit with the optimum performance along with the HPLC method was used for the determination of AFM1 in raw cow’s, goat’s, and sheep’s milk samples (396) obtained from producers in different regions of Greece. The evaluation of both methods showed that this ELISA kit could be considered as a faster and equally reliable alternative method to HPLC in routine analysis for the determination of AFM1 in milk.

scholarly journals Development and method validation for determination of 54 pesticides in Okra by LC-MS/MS analysis

2020 ◽  
Vol 11 (1) ◽  
pp. 985-992
Author(s):  
Hymavati Muppalla ◽  
Kiranmayi Peddi
Keyword(s):  
European Union ◽  
Pesticide Residues ◽  
High Performance ◽  
Limit Of Detection ◽  
Extraction Procedure ◽  
Mass Spectrometry Analysis ◽  
Limit Of Quantification ◽  
Spectrometry Analysis ◽  
Tandem Mass Spectrometry Analysis

The presence of pesticide residues in primary and derived agricultural products raises serious health concerns for consumers across the globe. The aim of the present study was to assess the level of pesticide residues in Okra in India. A multi-residue method for the quantification of fifty-four pesticides in okra is described in this work. The present study employed a modified quick, easy cheap, effective rugged and safe (QuEChERS) extraction procedure followed by UHPLC-MS/MS (Ultra-High-Performance Liquid Chromatography coupled to Tandem Mass Spectrometry) analysis. Validation of the method was according to the guidelines given by European Union SANCO/12571/2013. The levels of validation were 10.0, 50.0 and 100 µg kg-1. The following parameters such as linearity, the limit of detection (LOD) (nearer to 0.005 mg kg-1) and limit of quantification (LOQ) (nearer to 0.01 mg kg-1) were set to be acceptable. The trueness of the method for 54 pesticides in all Okra commodities was between 80-110% with satisfactory repeatability and within-run reproducibility except for the pesticide residues such as Thiamethoxam and Fenamidone. The measurement of uncertainty for each of the pesticide was below 50% and was estimated to be in the range of 5.37% - 10.71%, which meets the criteria established in the SANCO/12571/2013 document (European Union, 2013). This method is concluded to be applicable for the determination of pesticide residues in Okra.

scholarly journals Determination of Tianeptine in Tablets by High-Performance Liquid Chromatography with Fluorescence Detection

2007 ◽  
Vol 90 (3) ◽  
pp. 720-724
Author(s):  
Sevgi Tatar Ulu
Keyword(s):  
Lower Limit ◽  
High Performance ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Linear Calibration ◽  
Fluorescence Detector ◽  
Relative Standard ◽  
Validation Parameters ◽  
Limit Of Quantitation

Abstract A sensitive and selective high-performance liquid chromatographic method has been developed for the determination of tianeptine (Tia) in tablets. The method is based on derivatization of Tia with 4-chloro-7-nitrobenzofurazan (NBD-Cl). A mobile phase consisting of acetonitrile10 mM orthophosphoric acid (pH 2.5; 77 + 23) was used at a flow rate of 1 mL/min on a C18 column. The Tia-NBD derivative was monitored using a fluorescence detector, with emission set at 520 nm and excitation at 458 nm. Gabapentin was selected as an internal standard. Linear calibration graphs were obtained in the concentration range of 45300 ng/mL. The lower limit of detection (LOD) was 10 ng/mL at a signal-to-noise ratio of 4. The lower limit of quantitation (LOQ) was 45 ng/mL. The relative standard values for intra- and interday precision were <0.46 and <0.57%, respectively. The recovery of the drug samples ranged between 98.89 and 99.85%. No chromatographic interference from the tablet excipients was found. The proposed method was validated in terms of precision, robustness, recovery, LOD, and LOQ. All the validation parameters were within the acceptance range. The proposed method was applied for the determination of Tia in commercially available tablets. The results were compared with those obtained by an ultraviolet spectrophotometric method using t- and F-tests.

A Monoclonal Antibody-Based Enzyme-Linked Immunosorbent Assay for Determination of Homoharringtonine

Planta Medica ◽  
2018 ◽  
Vol 84 (14) ◽  
pp. 1038-1044 ◽  
Author(s):  
Benyakan Pongkitwitoon ◽  
Seiichi Sakamoto ◽  
Rika Nagamitsu ◽  
Waraporn Putalun ◽  
Hiroyuki Tanaka ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Immunosorbent Assay ◽  
Myeloid Leukemia ◽  
High Performance ◽  
Sodium Periodate ◽  
Limit Of Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Study Support ◽  
Mediated Oxidation

AbstractHomoharringtonine (HHT), also known as omacetaxine, is a natural compound found in the genus Cephalotaxus and is a promising pharmaceutical drug used for the treatment of chronic or accelerated phase chronic myeloid leukemia. As a tool for the quantitative determination of HHT, a specific monoclonal antibody against HHT (MAb 6A1) was generated by conjugates prepared via sodium periodate-mediated oxidation. The developed indirect competitive enzyme-linked immunosorbent assay (icELISA) using MAb 6A1 was found to be highly specific and sensitive with a limit of detection for HHT of 48.8 ng/mL. Validation assays to evaluate precision and accuracy of the method were conducted by the use of intra- and inter-assay analysis, recovery test, and comparison analysis between the amounts of HHT determined by ELISA and high-performance liquid chromatography. These results revealed that the established icELISA using MAb 6A1 is specific, sensitive, and reliable enough to be applied to the qualitative analysis for HHT. Furthermore, the results of this study support the usefulness of sodium periodate as a reagent for the conjugation between Cephalotaxus alkaloids and proteins for producing specific antibodies.

Transfer of aflatoxins from naturally contaminated feed to milk of Nili-Ravi buffaloes fed a mycotoxin binder

2016 ◽  
Vol 56 (10) ◽  
pp. 1637 ◽  
Author(s):  
N. Aslam ◽  
I. Rodrigues ◽  
D. M. McGill ◽  
H. M. Warriach ◽  
A. Cowling ◽  
...  
Keyword(s):  
Aflatoxin B1 ◽  
High Performance ◽  
Mean Value ◽  
Aflatoxin M1 ◽  
Enzyme Linked Immunosorbent Assay ◽  
Treatment Groups ◽  
Low Concentrations ◽  
Daily Concentration ◽  
The Mean ◽  
Carry Over

The objectives of this study were to observe the extent of transfer of aflatoxin B1 in feed to the aflatoxin M1 metabolite in milk in Nili-Ravi buffaloes and to evaluate the efficacy of a commercial mycotoxin binder (Mycofix, Biomin Singapore) incorporated into feed to minimise this transfer. Multiparous animals (n = 28) were randomly distributed to four groups corresponding to two treatments each with two levels of aflatoxin B1. Individual animals were exposed to naturally contaminated feed providing a total of 1475 µg/day (Groups A and B) or 2950 µg/day (Groups C and D) of aflatoxin B1. Groups B and D were given 50 g of mycotoxin binder daily mixed with feed whereas Groups A and C were kept as controls. Feed samples were analysed by reverse phase high performance liquid chromatography for aflatoxin B1 and milk samples were evaluated by enzyme-linked immunosorbent assay for the liver metabolite aflatoxin M1. The mean value of total daily aflatoxin M1 excretion for animals fed 2950 µg/day of aflatoxin B1 (112.6 µg/day) was almost double (P < 0.001) than the excretion in buffaloes fed 1475 µg/day (62.2 µg/day). The mean daily concentration of aflatoxin M1 in milk of animals from both treatment groups supplemented with 50 g/day of mycotoxin binder was 76.5 µg/day, nearly 22 µg lower than those without binder at 98.3 µg/day (s.e.d. = 5.99: P < 0.01). The interaction of binder and treatment was not significant i.e. the 50 g/day of binder was able to sequester aflatoxin B1 with the same efficiency in groups fed with high and low concentrations of aflatoxin B1. Carry over was (3.44%) lower (P = 0.001) in animals supplemented with 50 g/day of mycotoxin binder than those fed no binder (4.60%). Thus buffaloes are highly efficient at transferring aflatoxins in feed to the aflatoxin M1 metabolite in milk, whereas mycotoxin binder is capable of alleviating without preventing this contamination risk.

scholarly journals Comparative analysis of the effectiveness of analytical methods for the determination of aflatoxins in milk and dairy products (review information)

2020 ◽  
pp. 150-157
Author(s):  
S. Senin ◽  
V. Danchuk ◽  
S. Midyk ◽  
V. Ushkalov ◽  
O. Iakubchak
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Sample Preparation ◽  
Analytical Methods ◽  
Dairy Products ◽  
High Performance ◽  
Raw Milk ◽  
Enzyme Linked Immunosorbent Assay ◽  
Milk And Dairy Products

The dairy industry of Ukraine is developing dynamically, its needs for the quality of raw materials are growing significantly. Detection of mycotoxins in raw milk is one of the main indicators of its safety. The high degree of toxicity of mycotoxins is a threat to the health of the lactating animal, so a large number of them are excreted in milk. If we talk about ruminants, the vast majority of mycotoxins are utilized by microorganisms of the pancreas, which does not occur in monogastric animals, so the list of mycotoxins in their milk can be much wider than the secretion of mammalian mammals. To date, the maximum permissible levels (MRLs) of mycotoxins in raw milk and dairy products have been established. Thus, a comprehensive determination of the content of mycotoxins in the secretion of the breast has not only technological but also important diagnostic value. Milk sample preparation is the most important step in the determination of mycotoxins and consists of sampling, extraction and purification from impurities. For the extraction of aflatoxins, the method of liquid extraction with acetonitrile or chloroform is used. Purification of extracts is carried out on immunoaffinity columns, cartridges with special sorbents or using certain manufacturers (MycoSep®).Enzyme-linked immunosorbent assay and high-performance liquid chromatography with fluorescence detection are used to determine aflatoxin B1 and M1 in raw milk of cows. However, all these methods have a number of disadvantages, namely: long and expensive sample preparation and insufficiently high selectivity. Currently, the complex determination of mycotoxins in various matrices by high-performance liquid chromatography with mass spectrometric detection (LC-MS/MS) and the use of modified QuEChERS sample preparation is gaining popularity. The advantage of this technique is the combination of faster and cheaper sample preparation of QuEChERS samples with highly selective LC-MS/MS chromatography. Key words: mycotoxins, raw milk, analytical methods, QuEChERS.

Evaluation of intraocular penetration of levofloxacin by high performance liquid chromatography

2021 ◽  
Vol 2 (3) ◽  
pp. 155-158
Author(s):  
Mahsa Hasanzadeh ◽  
◽  
Amir Heydari ◽  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Cataract Surgery ◽  
High Performance ◽  
Topical Administration ◽  
Hplc Method ◽  
Fluorescence Detector ◽  
Wide Range ◽  
The Mean

AIM: To evaluate the levofloxacin eye drop into human eye penetration, levofloxacin eye drop concentrations in human ocular aqueous of 33 patients undergoing cataract surgery were measured by high performance liquid chromatography (HPLC). METHODS: Totally 33 volunteer patients who scheduled for phacoemulsification surgery received one drop of levofloxacin every 6h for 3d before and on the day of surgery, administration of drug was stopped 1h before surgery. Levofloxacin concentration in aqueous humor was measured by HPLC method with fluorescence detector. RESULTS: A simple, effective and sensitive HPLC method for determination of levofloxacin in human ocular aqueous was validated. Linearity was shown for levofloxacin concentration over a wide range of 1.95×10-3-1.50 µg/mL. The mean aqueous level of levofloxacin was 0.3399±0.03405 µg/mL. CONCLUSION: Results from the present study demonstrate that topical administration of levofloxacin 0.5% before cataract surgery with routine dose (one drop every 6h) unable to reach MIC90 for most common microorganism causing acute bacterial endophthalmitis.

scholarly journals Reliable HPLC Determination of Aflatoxin M1 in Eggs

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Mostafa M. H. Khalil ◽  
Ahmed M. Gomaa ◽  
Ahmed Salem Sebaei
Keyword(s):  
Aflatoxin B1 ◽  
High Performance ◽  
Limit Of Detection ◽  
Aflatoxin M1 ◽  
Limit Of Quantification ◽  
Chromatography Method ◽  
Animal Products ◽  
Liquid Chromatography Method ◽  
Different Levels

Aflatoxin M1 is the foremost metabolite of aflatoxin B1 in humans and animals, which may be present in animal products from animals fed with aflatoxin B1 contaminated feed. In this study a high performance liquid chromatography method for determination of aflatoxin M1 in eggs was described. The egg samples were diluted with warmed water and the toxin was immunoextracted followed by fluorescence detection. The average recovery of aflatoxin M1 at the three different levels 0.05, 0.1, and 0.5 μg/kg varied between 87% and 98%. The method is linear from the limit of quantification 0.05 μg/kg up to 3 μg/kg levels. This method is intended for aflatoxin M1 analyses in eggs simply with minimum toxin lose, excellent recovery, and accurate results with the limit of detection 0.01 μg/kg.

Development and Validation of Two New Methods for the Determination of Rilmenidine in Bulk and Pharmaceutical Preparation

2021 ◽  
Author(s):  
Elif Özdemir ◽  
Gamze Ergin Kizilçay ◽  
Sıdıka Ertürk Toker
Keyword(s):  
High Performance ◽  
Limit Of Detection ◽  
Pharmaceutical Preparation ◽  
Gradient Elution ◽  
Hplc Method ◽  
Fluorescence Detector ◽  
New Methods ◽  
Limit Of Quantitation ◽  
Development And Validation

Abstract In the present study, two new methods were developed and validated for the determination of rilmenidine in bulk and pharmaceutical preparation. Both methods are based on a derivatization reaction using 4-chloro-7-nitro-1,2,3-benzoxadiazole (NBD-Cl) as a fluorogenic substance. The drug reagent derivatives were formed by the reaction of rilmenidine with NBD-Cl at pH 9.0 at 70°C for 40 min. The reaction mixtures were analyzed by spectrofluorimetry in the first method and high performance liquid chromatography (HPLC) in the second method. Derivatives were determined at λex 493 nm and at λem 536 nm in the spectrofluorimetric method. The separation was performed place on a Phenomenex, C18 column (250 × 4.6 mm, 5 μm i.d) using a mobile phase comprising 0.2% formic acid and acetonitrile gradient elution mode in the HPLC method. Analytes were detected by a fluorescence detector at the same wavelength. The methods were validated for limit of quantitation, linearity, robustness, recovery, limit of detection, precision and accuracy. Calibration curves for the first and second methods were found to be linear in the range of 2.0–12.0 and 250–2000 ng/mL, respectively. Detection limits for the spectrofluorimetric and HPLC methods were calculated as 0.16 and 18.28 ng/mL, respectively. The validated methods were applied successfully to the determination of rilmenidine in bulk and pharmaceutical preparation.

High Performance Liquid Chromatography Method for Simultaneous Determination of Bisphenols in Plastic Packed dry Fruits Using Multiwalled Carbon Nanotubes as Solid Phase Extraction Sorbent

2020 ◽  
Vol 17 ◽  
Author(s):  
Hassan Y. Aboul-Enein ◽  
Abdalla Ahmed Elbashir ◽  
Mei Musa Ali Omar ◽  
Manahil Babiker Elamin ◽  
Shazalia Mahmoud Ahmed Ali
Keyword(s):  
Carbon Nanotubes ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Simultaneous Determination ◽  
High Performance ◽  
Limit Of Detection ◽  
Bisphenol S ◽  
Fluorescence Detector ◽  
Bisphenol F

Background: Bisphenols A (BPA), bisphenol S (BPS), and bisphenol F (BPF) are manufactured chemicals found in food packaging, drink containers, lotions, toys, plastic PVC flooring and water pipes. The aim of this work is to develop simple, rapid and reliable high-performance liquid chromatography with fluorescence detector (HPLC-FLD) method for simultaneous determination of bisphenols A (BPA), bisphenol F (BPF), and bisphenol S (BPS) in plastic packed dry fruits collected from Saudi Arabia markets. Methods: BPA, BPS and BPF in plastic packed dry fruits samples were extracted and clean up using packed Multi Walled Carbon Nanotubes (MWCNTs) mini-column followed by analysis using HPLC-FLD. Results: The three BPs were separated within less than 12 min. The method was validated in terms of linearity, limit of detection (LOD), limit of quantification (LOQ), precision (repeatability) and accuracy (recovery). Good linearity was obtained in concentration range of 62.25-10000 μg/L for BPS and 6.25-1000 μg/L for BPA and BPF. The LODs and LOQs were found to be 1.07, 12.09, and 0.9939 μg/L and 3.56, 40.32 and 3.13 μg/L for bisphenols BPA, BPS, and BPF, respectively. Recoveries for analytes in the samples were all within the range of 87% to 104%. Conclusion: The method was successfully applied to real dry fruit sample (i.e , dry date (Ajwa) , apricot, dry grapes and figs . The results obtained revealed that all of the tested BPs were present in the samples.

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