Quantitation and Stability of Fumonisins B1 and B2 in Milk

1994 ◽  
Vol 77 (5) ◽  
pp. 1162-1167 ◽  
Author(s):  
Chris M Maragos ◽  
John L Richard
Keyword(s):  
Liquid Chromatography ◽  
Limit Of Detection ◽  
Analytical Techniques ◽  
Enzyme Linked Immunosorbent Assay ◽  
Color Development ◽  
Strong Anion Exchange ◽  
Low Sensitivity ◽  
No Sample Preparation ◽  
Fumonisins B1 And B2 ◽  
Lower Heating

Abstract The well-documented presence of fumonisin myco-toxins B1 and B2 (FB1 and FB2) in corn raises the possibility that these toxins are carried over into the milk of animals fed with contaminated feed. The presence of FB1 and FB2 in milk has not been assessed because of the lack of sensitive analytical techniques for this matrix. Two methods, liquid chromatography (LC) and enzyme-linked immunosorbent assay (ELISA), were adapted for the analysis of milk. The ELISA, produced commercially for screening corn, required no sample preparation and was reproducible but was of low sensitivity [concentration that inhibits color development by 50% (IC50), 1200-1600 ng FB1/mL]. The more sensitive LC method involves serial extraction of milk with methanol-acetone and strong anion exchange followed by derivatization with naphthalene-2,3-dicarboxaldehyde. Recoveries of 50 ng FB1 and FB2/mL from unpasteurized and un-homogenized milk were 84 and 83%, respectively (limit of detection, 5 ng/mL). Recoveries of FB1 from whole homogenized milk (76%) were slightly lower. Heating milk for 30 min at 62°C, to mimic pasteurization, did not significantly reduce FB1 or FB2 recovery, nor did storing milk for 11 days at 4°C. The LC method was applied to 165 samples of milk, only 1 of which was positive. This finding suggests that exposure of humans to FB1 and FB2 from milk is low.

scholarly journals Efficiency of crude corn extract clean-up on different columns in fumonisins determination

2005 ◽  
pp. 95-102 ◽  
Author(s):  
Biljana Abramovic ◽  
Sandra Jaksic ◽  
Zoran Masic
Keyword(s):  
Liquid Chromatography ◽  
Anion Exchange ◽  
Fluorescence Detection ◽  
Crude Extract ◽  
Reversed Phase ◽  
Lower Price ◽  
Strong Anion Exchange ◽  
Chromatographic Resolution ◽  
Immunoaffinity Columns ◽  
Fumonisins B1 And B2

The efficiencies of different clean-up procedures for crude corn extract from corn samples naturally contaminated by fumonisins B1 and B2 were compared. These procedures precede liquid chromatography determination with fluorescence detection. The efficiencies of immunoaffinity columns (IMA) strong anion exchange columns (SAX), as well as columns with reversed-phase C18 (RP C18) were investigated. No significant differences in the obtained results were found, regardless of the crude extract clea-nup procedure. However, the use of IMA columns for clean-up provided better chromatographic resolution, with the clean-up procedure being the simplest and the fastest. Also, because of the possibility of IMA column regeneration, it is possible to prepare ten samples on one column, so all in all, the lower price of SAX and RP C18 columns is of no great significance.

scholarly journals Determination of Imazaquin Residues in Soil by Solid-Phase Extraction and High-Performance Liquid Chromatography

2007 ◽  
Vol 90 (2) ◽  
pp. 568-574 ◽  
Author(s):  
Chen Xuyan ◽  
Hu Jiye ◽  
Li Jianzhong
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Solid Phase Extraction ◽  
High Performance ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Phase Extraction ◽  
Application Rates ◽  
Relative Standard ◽  
Strong Anion Exchange

Abstract A method has been developed for the quantitation of imazaquin residues in soil. The herbicide was extracted from soil with methanolwater (2 + 1, v/v) and cleaned up by strong anion-exchange solid-phase extraction cartridges. Analysis was performed by using high-performance liquid chromatography with ultraviolet detection. Average recoveries through the method ranged from 90.7 to 100.6%, with relative standard deviation equal to or lower than 6.6%. The limit of detection was estimated to be 0.0015 mg/kg, and the minimum quantitation concentration of imazaquin in soil was 0.005 mg/kg. This method was successfully applied to evaluate imazaquin residue levels in soil and its dissipation rates in a soybean field in the Xisanqi District of Beijing, People's Republic of China. The dissipation study showed that the half life of imazaquin in soil was 10.37 0.0135 days at 3 different application rates.

scholarly journals Eco-Friendly Fluorescent ELISA Based on Bifunctional Phage for Ultrasensitive Detection of Ochratoxin A in Corn

Foods ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2429
Author(s):  
Weipeng Tong ◽  
Hao Fang ◽  
Hanpeng Xiong ◽  
Daixian Wei ◽  
Yuankui Leng ◽  
...  
Keyword(s):  
Ochratoxin A ◽  
Limit Of Detection ◽  
High Reliability ◽  
Ultra Performance Liquid Chromatography ◽  
Enzyme Linked Immunosorbent Assay ◽  
Enhanced Sensitivity ◽  
Great Specificity ◽  
Screening Platform ◽  
Mimic Peptide ◽  
Low Sensitivity

Conventional enzyme-linked immunosorbent assay (ELISA) is commonly used for Ochratoxin A (OTA) screening, but it is limited by low sensitivity and harmful competing antigens of enzyme-OTA conjugates. Herein, a bifunctional M13 bacteriophage with OTA mimotopes fused on the p3 protein and biotin modified on major p8 proteins was introduced as an eco-friendly competing antigen and enzyme container for enhanced sensitivity. Mercaptopropionic acid-modified quantum dots (MPA-QDs), which are extremely sensitive to hydrogen peroxide, were chosen as fluorescent signal transducers that could manifest glucose oxidase-induced fluorescence quenching in the presence of glucose. On these bases, a highly sensitive and eco-friendly fluorescent immunoassay for OTA sensing was developed. Under optimized conditions, the proposed method demonstrates a good linear detection of OTA from 4.8 to 625 pg/mL and a limit of detection (LOD) of 5.39 pg/mL. The LOD is approximately 26-fold lower than that of a conventional horse radish peroxidase (HRP) based ELISA and six-fold lower than that of a GOx-OTA conjugate-based fluorescent ELISA. The proposed method also shows great specificity and accepted accuracy for analyzing OTA in real corn samples. The detection results are highly consistent with those obtained using the ultra-performance liquid chromatography-fluorescence detection method, indicating the high reliability of the proposed method for OTA detection. In conclusion, the proposed method is an excellent OTA screening platform over a conventional ELISA and can be easily extended for sensing other analytes by altering specific mimic peptide sequences in phages.

scholarly journals Comparison of Four C18 Columns for the Liquid Chromatographic Determination of Deoxynivalenol in Naturally Contaminated Wheat

2007 ◽  
Vol 90 (4) ◽  
pp. 995-999 ◽  
Author(s):  
El-Sayed M Abdel-Aal ◽  
Kaddus Miah ◽  
J Christopher Young ◽  
Iwona Rabalski
Keyword(s):  
Liquid Chromatography ◽  
Retention Time ◽  
Limit Of Detection ◽  
Charge Ratio ◽  
Enzyme Linked Immunosorbent Assay ◽  
Atomic Mass Unit ◽  
Column Temperature ◽  
Mass Unit ◽  
Relative Standard ◽  
Limit Of Quantitation

Abstract Three long and 1 short reversed-phase C18 columns were compared for separation of deoxynivalenol (DON) in extracts of naturally contaminated wheat samples using liquid chromatography with ultraviolet detection and liquid chromatography/mass spectrometry (LC/MS). Among the 3 long columns used, a Symmetry C18 column with an isocratic solvent mixture of wateracetonitrilemethanol (90 + 5 + 5, v/v/v) gave the best separation for DON without interferences from other compounds in the wheat extracts. The Symmetry short (75 mm) column was comparable with the long column (250 mm) in resolving DON but significantly reduced retention time (i.e., 5.8 versus 16.3 min). Increasing the column temperature from 25 to 45C resulted in a further reduction in retention time. Identity of DON in the wheat extracts and standard solutions was confirmed by LC/MS in the positive ion mode, whereby DON appeared with an (M+1)+ ion at a mass-to-charge ratio of 297 plus fragment ions associated with loss of water and/or a 30 atomic mass unit (amu) CH2O fragment. The Symmetry short column was also capable of separating a mixture of the mycotoxins DON, 15-acetyl-DON, nivalenol, and zearalenone by use of a combination of an isocratic and gradient solvent system. The overall method showed high precision, exhibiting a relative standard deviation of 4.8%, limit of detection of 50 ng/g, and limit of quantitation of 165 ng/g. It was significantly correlated with enzyme-linked immunosorbent assay analysis, indicating its appropriateness for safety and quality assurance of wheat and related grains.

Development and Validation of A Reversed Phase-High Performance Liquid Chromatography Method for the Quantitative Estimation of Ramipril Drug Content from Formulated Dosage Form

2016 ◽  
Vol 6 (3) ◽  
Author(s):  
Raju Chandra ◽  
Manisha Pant ◽  
Harchan Singh ◽  
Deepak Kumar ◽  
Ashwani Sanghi
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Active Ingredient ◽  
High Performance ◽  
Limit Of Detection ◽  
Quantitative Estimation ◽  
Reversed Phase ◽  
Uv Detector ◽  
Chromatography Method ◽  
Drug Content

A reliable and reproducible reversed-phase high performance liquid chromatography (RP-HPLC) was developed for the quantitative determination of Remipril drug content from marketed bulk tablets. The active ingredient of Remipril separation achieved with C18 column using the methanol water mobile phase in the ratio of 40:60 (v/v). The active ingredient of the drug content quantify with UV detector at 215 nm. The retention time of Remipril is 5.63 min. A good linearity relation (R2=0.999) was obtained between drug concentration and average peak areas. The limit of detection and limit of quantification of the instrument were calculated 0.03 and 0.09 µg/mL, respectively. The accuracy of the method validation was determined 102.72% by recoveries method.

scholarly journals Rapid and Sensitive Detection of miRNA Based on AC Electrokinetic Capacitive Sensing for Point-of-Care Applications

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 3985
Author(s):  
Nan Wan ◽  
Yu Jiang ◽  
Jiamei Huang ◽  
Rania Oueslati ◽  
Shigetoshi Eda ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Point Of Care ◽  
Low Cost ◽  
Clinical Diagnostics ◽  
Detection Methods ◽  
Capacitive Sensing ◽  
Application Potential ◽  
Mirna Detection ◽  
Mirna 25 ◽  
Low Sensitivity

A sensitive and efficient method for microRNAs (miRNAs) detection is strongly desired by clinicians and, in recent years, the search for such a method has drawn much attention. There has been significant interest in using miRNA as biomarkers for multiple diseases and conditions in clinical diagnostics. Presently, most miRNA detection methods suffer from drawbacks, e.g., low sensitivity, long assay time, expensive equipment, trained personnel, or unsuitability for point-of-care. New methodologies are needed to overcome these limitations to allow rapid, sensitive, low-cost, easy-to-use, and portable methods for miRNA detection at the point of care. In this work, to overcome these shortcomings, we integrated capacitive sensing and alternating current electrokinetic effects to detect specific miRNA-16b molecules, as a model, with the limit of detection reaching 1.0 femto molar (fM) levels. The specificity of the sensor was verified by testing miRNA-25, which has the same length as miRNA-16b. The sensor we developed demonstrated significant improvements in sensitivity, response time and cost over other miRNA detection methods, and has application potential at point-of-care.

scholarly journals Pitfalls in the Immunochemical Determination of β‑Lactam Antibiotics in Water

Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 298
Author(s):  
Alexander Ecke ◽  
Rudolf J. Schneider
Keyword(s):  
Limit Of Detection ◽  
Cost Effective ◽  
Enzyme Linked Immunosorbent Assay ◽  
Degree Of Hydrolysis ◽  
Site Analysis ◽  
Antibody Recognition ◽  
Immunochemical Determination ◽  
Key Factor ◽  
Lactam Ring

Contamination of waters with pharmaceuticals is an alarming problem as it may support the evolution of antimicrobial resistance. Therefore, fast and cost-effective analytical methods for potential on-site analysis are desired in order to control the water quality and assure the safety of its use as a source of drinking water. Antibody-based methods, such as the enzyme-linked immunosorbent assay (ELISA), can be helpful in this regard but can also have certain pitfalls in store, depending on the analyte. As shown here for the class of β-lactam antibiotics, hydrolysis of the β‑lactam ring is a key factor in the immunochemical analysis as it influences antibody recognition. With the antibody used in this study, the limit of detection (LOD) in the immunoassay could be significantly reduced by hydrolysis for the five tested penicillins, with the lowest LOD for carbenicillin (0.2 nmol/L) and the greatest impact on penicillins G and V (reduction by 85%). In addition to enhanced quantification, our strategy also provides access to information about the degree of hydrolysis in water samples as shown for the most abundant penicillin amoxicillin.

scholarly journals Quantification of plasma remdesivir and its metabolite GS-441524 using liquid chromatography coupled to tandem mass spectrometry. Application to a Covid-19 treated patient

2020 ◽  
Vol 58 (9) ◽  
pp. 1461-1468 ◽  
Author(s):  
Jean-Claude Alvarez ◽  
Pierre Moine ◽  
Isabelle Etting ◽  
Djillali Annane ◽  
Islam Amine Larabi
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Half Life ◽  
Limit Of Detection ◽  
Treated Patient ◽  
Internal Standard ◽  
Therapeutic Drug ◽  
Active Metabolites ◽  
Limit Of Quantification ◽  
Positive Mode

AbstractObjectivesA method based on liquid chromatography coupled to triple quadrupole mass spectrometry detection using 50 µL of plasma was developed and fully validated for quantification of remdesivir and its active metabolites GS-441524.MethodsA simple protein precipitation was carried out using 75 µL of methanol containing the internal standard (IS) remdesivir-13C6 and 5 µL ZnSO4 1 M. After separation on Kinetex® 2.6 µm Polar C18 100A LC column (100 × 2.1 mm i.d.), both compounds were detected by a mass spectrometer with electrospray ionization in positive mode. The ion transitions used were m/z 603.3 → m/z 200.0 and m/z 229.0 for remdesivir, m/z 292.2 → m/z 173.1 and m/z 147.1 for GS-441524 and m/z 609.3 → m/z 206.0 for remdesivir-13C6.ResultsCalibration curves were linear in the 1–5000 μg/L range for remdesivir and 5–2500 for GS-441524, with limit of detection set at 0.5 and 2 μg/L and limit of quantification at 1 and 5 μg/L, respectively. Precisions evaluated at 2.5, 400 and 4000 μg/L for remdesivir and 12.5, 125, 2000 μg/L for GS-441524 were lower than 14.7% and accuracy was in the [89.6–110.2%] range. A slight matrix effect was observed, compensated by IS. Higher stability of remdesivir and metabolite was observed on NaF-plasma. After 200 mg IV single administration, remdesivir concentration decrease rapidly with a half-life less than 1 h while GS-441524 appeared rapidly and decreased slowly until H24 with a half-life around 12 h.ConclusionsThis method would be useful for therapeutic drug monitoring of these compounds in Covid-19 pandemic.

Determination of Free Solanesol Levels in Cigarette Filters by Liquid Chromatography–Mass Spectrometry

2021 ◽  
Author(s):  
Roberto Bravo Cardenas ◽  
Phuong Ngac ◽  
Clifford Watson ◽  
Liza Valentin-Blasini
Keyword(s):  
Liquid Chromatography ◽  
Sample Preparation ◽  
Tobacco Smoke ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Filter Material ◽  
Previous Method ◽  
Tobacco Smoke Exposure ◽  
Triple Quadrupole Mass Spectrometer ◽  
Cigarette Butts

Abstract Solanesol, a naturally occurring constituent of tobacco, has been utilized as a good marker for environmental tobacco smoke particulate and as a noninvasive predictor of mainstream cigarette smoke tar and nicotine intake under naturalistic smoking conditions. A fast and accurate method for measuring free solanesol to assess tobacco smoke exposure is highly desirable. We have developed and validated a new environmentally friendly, high-throughput method for measuring solanesol content in discarded cigarette filter butts. The solanesol deposited in the used filters can be correlated with mainstream smoke deliveries of nicotine and total particle matter to estimate constituent delivery to smokers. A portion of filter material is removed from cigarette butts after machine smoking, spiked with internal standard solution, extracted and quantitatively analyzed using reverse-phase liquid chromatography coupled to a triple-quadrupole mass spectrometer. The new method incorporates a 48-well plate format for automated sample preparation that reduces sample preparation time and solvent use and increases sample throughput 10-fold compared to our previous method. Accuracy and precision were evaluated by spiking known amounts of solanesol on both clean and smoked cigarette butts. Recoveries exceeded 93% at both low and high spiking levels. Linear solanesol calibration curves ranged from 1.9 to 367 µg/butt with a 0.05 µg/butt limit of detection.

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