Detection of ochratoxin A based on the use of its diastereoisomer as an internal standard

2014 ◽  
Vol 6 (15) ◽  
pp. 5610-5614 ◽  
Author(s):  
Mohamed Attya ◽  
Leonardo Di Donna ◽  
Fabio Mazzotti ◽  
Alessia Fazio ◽  
Bartolo Gabriele ◽  
...  
Keyword(s):  
Ochratoxin A ◽  
Internal Standard ◽  
Standard Approach

A new methodology for the determination of ochratoxin A (OTA) was developed using a diastereoisomeric internal standard approach and HPLC-FLD.

scholarly journals Comparison of Flow Injection-MS/MS and LC-MS/MS for the Determination of Ochratoxin A

Toxins ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 547
Author(s):  
Kai Zhang
Keyword(s):  
Ochratoxin A ◽  
Flow Injection ◽  
Internal Standard ◽  
Grape Juice ◽  
Tandem Mass ◽  
Triple Quadrupole ◽  
On Line ◽  
Red Grape Juice ◽  
Red Grape

Two methods for measuring ochratoxin A in corn, oat, and grape juice were developed and compared. Flow injection (FI) and on-line liquid chromatography (LC) performances were evaluated separately, with both methods using a triple quadrupole tandem mass spectrometer (MS/MS) for quantitation. Samples were fortified with 13C uniformly labeled ochratoxin A as the internal standard (13C-IS) and prepared by dilution and filtration, followed by FI- and LC-MS/MS analysis. For the LC-MS/MS method, which had a 10 min run time/sample, recoveries of ochratoxin A fortified at 1, 5, 20, and 100 ppb in corn, oat, red grape juice, and white grape juice ranged from 100% to 117% with RSDs < 9%. The analysis time of the FI-MS/MS method was <60 s/sample, however, the method could not detect ochratoxin A at the lowest fortification concentration, 1 ppb, in all tested matrix sources. At 5, 20, and 100 ppb, recoveries by FI-MS/MS ranged from 79 to 117% with RSDs < 15%. The FI-MS/MS method also had ~5× higher solvent and matrix-dependent instrument detection limits (0.12–0.35 ppb) compared to the LC-MS/MS method (0.02–0.06 ppb). In the analysis of incurred corn and oat samples, both methods generated comparable results within ±20% of reference values, however, the FI-MS/MS method failed to determine ochratoxin A in two incurred wheat flour samples due to co-eluted interferences due to the lack of chromatographic separation.

scholarly journals Development and validation of a SPE-UHPLC-fluorescence method for the analysis of ochratoxin-a in certain Turkish wines

2019 ◽  
Vol 38 (2) ◽  
pp. 161
Author(s):  
Elif Mine Oncu Kaya
Keyword(s):  
Ochratoxin A ◽  
Mobile Phase ◽  
High Performance ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Internal Standard ◽  
Fluorescence Method ◽  
Limit Of Quantitation ◽  
Development And Validation

A sensitive Ultra-High Performance Liquid Chromatography (UHPLC)-fluorescence method was developed and validated for the determination of ochratoxin-A (OTA) in Turkish wine samples. Naphthalene was used as an internal standard in this study. OTA was separated on a C18 (3.0 mm × 100 mm × 1.8 µm) column and analyses were run under isocratic conditions, with a mobile phase consisting of water/acetonitrile/acetic acid (50:50:1, v/v/v). The flow rate and injection volume were 0.5 ml min−1 and 10 μl, respectively. The excitation and emission wavelengths were 330 nm and 460 nm for OTA, respectively, and 220 nm and 325 nm for internal standard, respectively. A solid-phase extraction (SPE) clean-up procedure on a C18 cartridge was used prior to the analysis of the wine samples by UHPLC. The developed method was validated with respect to linearity, precision, accuracy, limit of detection (LOD), limit of quantitation (LOQ), stability and robustness. The method presented good RSD (< 4 %) and recovery (102.6–105.2 %) values. The LOD and LOQ values were 0.01 ng ml–1 and 0.05 ng ml–1, respectively. All other parameters were acceptable. OTA amounts were found in the range of 2.72‒7.40 µg kg‒1 in the Turkish wine samples.

scholarly journals HPLC fluorescence determination of ochratoxin A utilizing a double internal standard and its application to poultry feed

2015 ◽  
Vol 39 ◽  
pp. 372-381 ◽  
Author(s):  
Muzaffer TUNÇEL ◽  
Elif Mine ÖNCÜ KAYA ◽  
Ülkü Dilek UYSAL ◽  
Tufan GÜRAY
Keyword(s):  
Ochratoxin A ◽  
Internal Standard ◽  
Poultry Feed ◽  
Fluorescence Determination

Determination of non-metallic inclusions in metal alloys by spark atomic emission spectrometry (review)

2018 ◽  
Vol 84 (12) ◽  
pp. 5-19
Author(s):  
D. N. Bock ◽  
V. A. Labusov
Keyword(s):  
Spectral Line ◽  
Internal Standard ◽  
Detection Limits ◽  
Radiation Detectors ◽  
Metal Alloys ◽  
Emission Spectrometry ◽  
Direct Production ◽  
Metallic Inclusions ◽  
Dissolved Form

A review of publications regarding detection of non-metallic inclusions in metal alloys using optical emission spectrometry with single-spark spectrum registration is presented. The main advantage of the method - an extremely short time of measurement (~1 min) – makes it useful for the purposes of direct production control. A spark-induced impact on a non-metallic inclusion results in a sharp increase (flashes) in the intensities of spectral lines of the elements that comprise the inclusion because their content in the metal matrix is usually rather small. The intensity distribution of the spectral line of the element obtained from several thousand of single-spark spectra consists of two parts: i) the Gaussian function corresponding to the content of the element in a dissolved form, and ii) an asymmetric additive in the region of high intensity values ??attributed to inclusions. Their quantitative determination is based on the assumption that the intensity of the spectral line in the single-spark spectrum is proportional to the content of the element in the matter ablated by the spark. Thus, according to the calibration dependence constructed using samples with a certified total element content, it is possible not only to determine the proportions of the dissolved and undissolved element, but also the dimensions of the individual inclusions. However, determination of the sizes is limited to a range of 1 – 20 µm. Moreover, only Al-containing inclusions can be determined quantitatively nowadays. Difficulties occur both with elements hardly dissolved in steels (O, Ca, Mg, S), and with the elements which exhibit rather high content in the dissolved form (Si, Mn). It is also still impossible to determine carbides and nitrides in steels using C and N lines. The use of time-resolved spectrometry can reduce the detection limits for inclusions containing Si and, possibly, Mn. The use of the internal standard in determination of the inclusions can also lower the detection limits, but may distort the results. Substitution of photomultipliers by solid-state linear radiation detectors provided development of more reliable internal standard, based on the background value in the vicinity of the spectral line. Verification of the results is difficult in the lack of standard samples of composition of the inclusions. Future studies can expand the range of inclusions to be determined by this method.

Determination of ochratoxin A in wine by direct analysis in real time-tandem mass spectrometry

2017 ◽  
Vol 35 (2) ◽  
pp. 185 ◽  
Author(s):  
Xiaoming GONG ◽  
Ronghui MA ◽  
Hongtao WANG ◽  
Liqiang GUO ◽  
Kai LI ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Real Time ◽  
Ochratoxin A ◽  
Direct Analysis ◽  
Tandem Mass
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