Effectiveness of hermetic technologies in limiting aflatoxin B1 and fumonisin B1 contamination of stored maize grain under smallholder conditions in Zimbabwe

2018 ◽  
Vol 11 (3) ◽  
pp. 459-469 ◽  
Author(s):  
T.C. Murashiki ◽  
C. Chidewe ◽  
M.A. Benhura ◽  
L.R. Manema ◽  
B.M. Mvumi ◽  
...  

There is limited empirical evidence on the efficacy of hermetic storage containers in reducing mycotoxin occurrence in stored maize grain under smallholder field conditions. Levels of aflatoxin B1 (AFB1) and fumonisin B1 (FB1) in maize samples collected from hermetic metal silos (148), hermetic grain bags (121) and conventional stores (179) during 2015 and 2016 storage seasons in two rural districts of Zimbabwe were assessed. AFB1 was determined using high performance liquid chromatography with post-column derivatisation and fluorescence detection, whilst FB1 was determined using direct competitive ELISA. All maize samples collected at harvest in 2015 and 2016 seasons contained FB1 at levels ranging from 10 to 462 μg/kg and 13 to 537 μg/kg, respectively. Use of hermetic containers did not seem to have any effect on the development of FB1 in stored maize grain, as there was no significant difference (P>0.05) in the increase of FB1 contamination in hermetic and conventional stores. Prior to storage, the levels of AFB1 in the maize ranged from below the limit of quantitation (LOQ) to 25.0 μg/kg, whilst levels during storage ranged from <LOQ to 8.60 μg/kg in hermetic silos, <LOQ to 8.37 μg/kg in hermetic bags and <LOQ to 791 μg/kg in conventional stores over the two storage seasons. The occurrence of AFB1 in maize stored in hermetic containers, was significantly (P<0.05) lower than that in conventional stores. Hermetic containers were more effective than conventional stores in limiting contamination of maize with AFB1 and subsequent human exposure to these toxins. Therefore, hermetic storage containers are recommended to smallholder maize producers for safe and effective limitation of AFB1 contamination during storage and hence reduce exposure among consumers.

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Sasiprapa Choochuay ◽  
Jutamas Phakam ◽  
Prakorn Jala ◽  
Thanapoom Maneeboon ◽  
Natthasit Tansakul

A reliable and rapid method has been developed for the determination of aflatoxin B1 (AFB1) in four kinds of feedstuffs comprising broken rice, peanuts, corn, and fishmeal. A sample preparation was carried out based on the QuEChERS method with the exclusion of the clean-up step. In this study, AFB1 was extracted using acetonitrile/methanol (40/60 v/v), followed by partitioning with sodium chloride and magnesium sulfate. High-performance liquid chromatography with precolumn derivatization and fluorescence detection was performed. The coefficients of determination were greater than 0.9800. Throughout the developed method, the recovery of all feedstuffs achieved a range of 82.50-109.85% with relative standard deviation lower than 11% for all analytes at a concentration of 20-100 ng/g. The limit of detection (LOD) ranged from 0.2 to 1.2 ng/g and limit of quantitation (LOQ) ranged from 0.3 to 1.5 ng/g. The validated method was successfully applied to a total of 120 samples. The occurrence of AFB1 contamination was found at the following concentrations: in broken rice (0.44-2.33ng/g), peanut (3.97-106.26ng/g), corn (0.88-50.29 ng/g), and fishmeal (1.06-10.35 ng/g). These results indicate that the proposed method may be useful for regularly monitoring AFB1 contamination in feedstuffs.


2008 ◽  
Vol 91 (3) ◽  
pp. 530-535 ◽  
Author(s):  
Bashar A AlKhalidi ◽  
Majed Shtaiwi ◽  
Hatim S AlKhatib ◽  
Mohammad Mohammad ◽  
Yasser Bustanji

Abstract A fast and reliable method for the determination of repaglinide is highly desirable to support formulation screening and quality control. A first-derivative UV spectroscopic method was developed for the determination of repaglinide in tablet dosage form and for dissolution testing. First-derivative UV absorbance was measured at 253 nm. The developed method was validated for linearity, accuracy, precision, limit of detection (LOD), and limit of quantitation (LOQ) in comparison to the U.S. Pharmacopeia (USP) column high-performance liquid chromatographic (HPLC) method. The first-derivative UV spectrophotometric method showed excellent linearity [correlation coefficient (r) = 0.9999] in the concentration range of 135 g/mL and precision (relative standard deviation &lt;1.5). The LOD and LOQ were 0.23 and 0.72 g/mL, respectively, and good recoveries were achieved (98101.8). Statistical comparison of results of the first-derivative UV spectrophotometric and the USP HPLC methods using the t-test showed that there was no significant difference between the 2 methods. Additionally, the method was successfully used for the dissolution test of repaglinide and was found to be reliable, simple, fast, and inexpensive.


2007 ◽  
Vol 70 (1) ◽  
pp. 151-156 ◽  
Author(s):  
AGUSTÍN ARIÑO ◽  
TERESA JUAN ◽  
GLORIA ESTOPAÑAN ◽  
JOSÉ F. GONZÁLEZ-CABO

Sixty samples of corn from both conventional and organic farms were tested for internal fungal contamination. Molds were identified to genus, and those belonging to the genus Fusarium were identified to species. Twenty isolates of Fusarium verticillioides were tested with a high-performance liquid chromatography–naphthalene dicarboxaldehyde–fluorescence method for their ability to produce fumonisins B1 and B2. The internal fungal infection in organic maize (63.20%) was significantly higher than that in conventional maize (40.27%) (P &lt; 0.05). However, the distribution of fungal genera indicated a significantly higher prevalence of Fusarium in conventional (34.93%) than in organic (18.15%) maize, making Fusarium the predominant fungus in conventional maize. This difference in mold distribution between organic and conventional maize was attributed to the difference in cultivation system. The dominant Fusarium species in both conventional and organic samples was F. verticillioides. There were no significant differences in the ability of 20 selected isolates of F. verticillioides to produce fumonisins on conventional or organic corn. Up to 13.3% of the conventional corn samples contained fumonisins B1 and B2 at mean concentrations of 43 and 22 ng/g, respectively. Organic corn samples had somewhat lower levels of contamination: 35 ng/g fumonisin B1 and 19 ng/g fumonisin B2 (P &gt; 0.05). The organic farming system, with well-balanced crop rotation, tillage, and compost fertilization, produced corn that was less likely to be contaminated with Fusarium species, although no significant difference in fumonisin concentrations was found between the two types of contaminated corn.


2008 ◽  
Vol 91 (1) ◽  
pp. 52-58 ◽  
Author(s):  
Jlia Menegola ◽  
Martin Steppe ◽  
Elfrides E S Schapoval

Abstract Column high-performance liquid chromatographic (LC) and UV spectrophotometric methods for the quantitative determination of citalopram, a potent and selective serotonin reuptake inhibitor, in tablets were developed. The parameters linearity, precision, accuracy, specificity, robustness, limit of detection, and limit of quantitation were studied according to International Conference on Harmonization guidelines. Chromatography was carried out by the reversed-phase technique on an ACE C18 column with a mobile phase composed of 0.30 triethylamine solutionacetonitrile (55 + 45, v/v) adjusted to pH 6.6 with 10 ortho-phosphoric acid at a flow rate of 1.0 mL/min and 25C. The UV spectrophotometric method was performed at 239 nm. The linearity of the LC method was in the range of 10.0070.00 g/mL, and 2.5017.50 g/mL for the UV spectrophotometric method. The interday and intraday assay precision was &lt;1.5 (relative standard deviation) for the LC and UV spectrophotometric methods. The recoveries were in the range 100.70101.35 for the LC method and 98.4898.65 for the UV spectrophotometric method. Statistical analysis by Student's t-test showed no significant difference between the results obtained by the 2 methods. The proposed methods are highly sensitive, precise, and accurate and can be used for the reliable quantitation of citalopram in tablets.


2019 ◽  
Vol 15 (3) ◽  
pp. 273-279
Author(s):  
Shweta G. Rangari ◽  
Nishikant A. Raut ◽  
Pradip W. Dhore

Background:The unstable and/or toxic degradation products may form due to degradation of drug which results into loss of therapeutic activity and lead to life threatening condition. Hence, it is important to establish the stability characteristics of drug in various conditions such as in temperature, light, oxidising agent and susceptibility across a wide range of pH values.Introduction:The aim of the proposed study was to develop simple, sensitive and economic stability indicating high performance thin layer chromatography (HPTLC) method for the quantification of Amoxapine in the presence of degradation products.Methods:Amoxapine and its degraded products were separated on precoated silica gel 60F254 TLC plates by using mobile phase comprising of methanol: toluene: ammonium acetate (6:3:1, v/v/v). The densitometric evaluation was carried out at 320 nm in reflectance/absorbance mode. The degradation products obtained as per ICH guidelines under acidic, basic and oxidative conditions have different Rf values 0.12, 0.26 and 0.6 indicating good resolution from each other and pure drug with Rf: 0.47. Amoxapine was found to be stable under neutral, thermal and photo conditions.Results:The method was validated as per ICH Q2 (R1) guidelines in terms of accuracy, precision, ruggedness, robustness and linearity. A good linear relationship between concentration and response (peak area and peak height) over the range of 80 ng/spot to 720 ng/spot was observed from regression analysis data showing correlation coefficient 0.991 and 0.994 for area and height, respectively. The limit of detection (LOD) and limit of quantitation (LOQ) for area were found to be 1.176 ng/mL and 3.565 ng/mL, whereas for height, 50.063 ng/mL and 151.707 ng/mL respectively.Conclusion:The statistical analysis confirmed the accuracy, precision and selectivity of the proposed method which can be effectively used for the analysis of amoxapine in the presence of degradation products.


Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2890
Author(s):  
Chikere G. Nkwonta ◽  
Macdara O’Neill ◽  
Niharika Rahman ◽  
Mary Moloney ◽  
Patrick J. Forrestal ◽  
...  

N-(n-butyl) thiophosphoric triamide (NBPT) is a urease inhibitor utilised in urea-based fertilizers. In Ireland, fertilizer treated with NBPT is applied to pasture to mitigate both ammonia and nitrous oxide emissions, but concerns arise as to the potential for residues in milk products. A quick ultrafiltration extraction and ultra-high performance liquid chromatography coupled with mass spectrometry triple quadrupole (UHPLC-MS/MS) quantitation method was developed and validated in this study. The method was applied in the analysis of samples collected from a field study investigating potential transfer of NBPT residues into milk. NBPT and NBPTo residues, were extracted from fortified milk samples and analysed on a UHPLC-MS/MS with recoveries ranging from 74 to 114%. Validation of the UHPLC-MS/MS method at low (0.0020 mg kg−1) and high (0.0250 mg kg−1) concentration levels in line with SANTE/12682/2019 showed overall trueness in the range of 99 to 104% and precision between 1 and 10%, RSD for both compounds. The limit of quantitation (LOQ) was 0.0020 mg kg−1 and other tested parameters (linearity, sensitivity, specificity, matrix effect, robustness, etc.) satisfied acceptance criteria. Stability assessment using spiked samples revealed the compounds were stable in raw and pasteurised milk for 4 weeks at –80 °C storage temperature. Maintaining samples at pH 8.5–9.0 further improved stability. Analysis of 516 milk samples from the field study found that NBPT and NBPTo concentrations were below the LOQ of 0.0020 mg kg−1, thus suggesting very low risk of residues occurring in the milk. The method developed is quick, robust, and sensitive. The method is deemed fit-for-purpose for the simultaneous determination of NBPT and NBPTo in milk.


2021 ◽  
Vol 64 (1) ◽  
Author(s):  
Hyeon Ji Yeo ◽  
Seung-A Baek ◽  
Ramaraj Sathasivam ◽  
Jae Kwang Kim ◽  
Sang Un Park

AbstractThis study aimed to comprehensively analyze primary and secondary metabolites of three different-colored (white, pale green, and green) pak choi cultivars (Brassica rapa subsp. chinensis) using gas chromatography attached with time-of-flight mass spectrometry (GC-TOFMS) and high-performance liquid chromatography (HPLC). In total, 53 primary metabolites were identified and subjected to partial least-squares discriminant analysis. The result revealed a significant difference in the primary and secondary metabolites between the three pak choi cultivars. In addition, 49 hydrophilic metabolites were detected in different cultivars. Total phenolic and glucosinolate contents were highest in the pale green and green cultivars, respectively, whereas total carotenoid and chlorophyll contents were highest in the white cultivar. Superoxide dismutase activity, 2,2-diphenyl-1-picrylhydraz scavenging, and reducing power were slightly increased in the white, pale green, and green cultivars, respectively. In addition, a negative correlation between pigments and phenylpropanoids was discovered by metabolite correlation analysis. This approach will provide useful information for the development of strategies to enhance the biosynthesis of phenolics, glucosinolates, carotenoids, and chlorophyll, and to improve antioxidant activity in pak choi cultivars. In addition, this study supports the use of HPLC and GC-TOFMS-based metabolite profiling to explore differences in pak choi cultivars.


Author(s):  
MADHURIMA BASAK ◽  
Santhosh Reddy Gouru ◽  
Animesh Bera ◽  
Krishna veni Nagappan

Objective: The present study aims at developing an accurate precise, rapid and sensitive Reverse Phase High-Performance Liquid Chromatography (RP-HPLC) method for assessing Empagliflozin in bulk drug and in the pharmaceutical dosage form. Methods: The proposed method employs a Reverse Phase Shim Pack C18 column (250 mm × 4.6 mm id; 5 µm) using a mobile phase comprising of acetonitrile and water in the ratio of 60:40 v/v flushed at a flow rate of 1 ml/min. The eluents were monitored at 223 nm. Results: Empagliflozin was eluted at a retention time of 5.417 min and established a co-relation co-efficient (R2>0.999) over a concentration ranging from 0.0495-100µg/ml. Percentage recovery was obtained between 98-102% which indicated that the method is accurate. The Limit of Detection (LOD) and Limit of Quantitation (LOQ) were found at 0.0125µg/ml and 0.0495µg/ml, respectively. Conclusion: An RP-HPLC method which was relatively simple, accurate, rapid and precise was developed and its validation was performed for the quantitative analysis of empagliflozin in bulk and tablet dosage form (10 and 25 mg) in accordance to International Conference of Harmonization (ICH) Q2 (R1) guidelines. The proposed method may aid in routinely analyzing empagliflozin in pharmaceuticals.


Author(s):  
Dilshad Ahmad ◽  
Faisal A. Al Meshaiti ◽  
Yazeed K. Al Anazi ◽  
Osama Al Owassil ◽  
Alaa Eldeen B. Yassin

Anastrozole, an aromatase inhibitor drug, is used for the treatment of breast cancer in pre- and postmenopausal women. Anastrozole’s incorporation into nanoparticulate carriers would enhance its therapeutic performance. To perceive the exact loaded amount of drug in nanocarriers, a valid analytical method is required. The reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed and validated by using the C18 column, 150 × 4.6 mm, 5 µm particle size, in isocratic mobile phase composed of 50:50 V/V (volume/volume) acetonitrile–phosphate buffer (pH 3) flowing at a rate of 1.0 mL/min, and a diode array detector (DAD) set at λmax = 215 nm. The validation parameters such as linearity, accuracy, specificity, precision, and robustness have proven the accuracy of the method, with the relative standard deviation percentage (% RSD) values < 2. The limit of detection of the method was found equal to 0.0150 µg/mL, and the limit of quantitation was 0.0607 µg/mL. The percent recovery of sample was in the range of 98.04–99.25%. The method has the advantage of being rapid with a drug retention time of 2.767 min, specific in terms of resolution of peaks void of interference with any of the excipients, and high reproducibility. This makes it highly applicable for quality control purposes.


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