Multidimensional Liquid Chromatographic Separations Applied to the Analysis of Food Samples

2008 ◽  
Vol 31 (11-12) ◽  
pp. 1758-1807 ◽  
Author(s):  
P. Dugo ◽  
T. Kumm ◽  
F. Cacciola ◽  
G. Dugo ◽  
L. Mondello
2020 ◽  
Vol 16 (3) ◽  
pp. 277-286
Author(s):  
Amal A. El-Masry ◽  
Mohammed E. A. Hammouda ◽  
Dalia R. El-Wasseef ◽  
Saadia M. El-Ashry

Background: The first highly sensitive, rapid and specific green microemulsion liquid chromatographic (MELC) method was established for the simultaneous estimation of fluticasone propionate (FLU) and azelastine HCl (AZL) in the presence of their pharmaceutical dosage form additives (phenylethyl alcohol (PEA) and benzalkonium chloride (BNZ)). Methods: The separation was performed on a C18 column using (o/w) microemulsion as a mobile phase which contains 0.2 M sodium dodecyl sulphate (SDS) as surfactant, 10% butanol as cosurfactant, 1% n-octanol as internal phase and 0.3% triethylamine (TEA) adjusted at pH 6 by 0.02 M phosphoric acid; with UV detection at 220 nm and programmed with flow rate of 1 mL/min. Results: The validation characteristics e.g. linearity, lower limit of quantification (LOQ), lower limit of detection (LOD), accuracy, precision, robustness and specificity were investigated. The proposed method showed linearity over the concentration range of (0.5-25 µg/mL) and (0.1-25 µg/mL) for FLU and AZL, respectively. Besides that, the method was adopted in a short chromatographic run with satisfactory resolution factors of (2.39, 3.78 and 6.74 between PEA/FLU, FLU/AZL and AZL/BNZ), respectively. The performed method was efficiently applied to pharmaceutical nasal spray with (mean recoveries ± SD) (99.80 ± 0.97) and (100.26 ± 0.96) for FLU and AZL, respectively. Conclusion: The suggested method was based on simultaneous determination of FLU and AZL in the presence of PEA and BNZ in pure form, laboratory synthetic mixture and its combined pharmaceutical dosage form using green MELC technique with UV detection. The proposed method appeared to be superior to the reported ones of being more sensitive and specific, as well as the separation was achieved with good performance in a relatively short analysis time (less than 7.5 min). Highly acceptable values of LOD and % RSD make this method superior to be used in quality control laboratories with of HPLC technique.


RSC Advances ◽  
2018 ◽  
Vol 8 (17) ◽  
pp. 9277-9286 ◽  
Author(s):  
Nadeem Muhammad ◽  
Fenglian Wang ◽  
Qamar Subhani ◽  
Qiming Zhao ◽  
Muhammad Abdul Qadir ◽  
...  

A 2D-IC system was successfully fabricated for clean isocratic chromatographic separations and sensitive post column UV induced fluorescence determination of two NNIs in six complex food samples.


1989 ◽  
Vol 93 (3) ◽  
pp. 391-401
Author(s):  
T. H. DUNNEBACKE ◽  
J. S. DIXON

An amebic component NACM (Naegleria ameba cytopathogenic material) is obtained from free-living amebae and acts as a cytopathogen in cultured avian and mammalian cells. NACM has been purified and partially characterized using a scheme that includes ammonium sulfate precipitation, liquid chromatographic separations and electrophoretic isolations. The purified NACM product is biologically active. Its properties, revealed by its behavior following treatment with enzymes and during purification, are those of a protein; its size is in the molecular weight range of 36000 and it has an isoelectric point of pH4.2. Monoclonal antibodies have been produced to NACM that prevent its cytopathic activity, and, in dot-blot procedures, identify purified NACM-containing fractions. When used as immunostains, NACM antibodies disclose the presence of immunospecific material both in the amebae and in vertebrate cells inoculated with NACM. In the amebae, the immunostain is located at the tips of the pseudopodia and in the peripheral cytoplasm; in the vertebrate cells, it is absent in uninoculated cells and is not observed in the inoculated cells for the first 3–4 days after the addition of the NACM to the culture. Subsequently, in a time course associated with the development of cytopathic changes observed in the light microscope, immunostaining material develops in the perinuclear cytoplasm where it condenses into a large mass before the cells undergo lysis. On the basis of these results, it appears that NACM represents an unprecedented system in which a protein material from an organism, in the course of destroying unrelated cells, causes the production of a cytoplasmic product that is immunologically recognizable as the inoculating amebic material.


2003 ◽  
Vol 86 (4) ◽  
pp. 753-758 ◽  
Author(s):  
Samo Andrensek ◽  
Alenka Golc-Wondra ◽  
Mirko Prosek

Abstract Phenylketonuria is a common metabolic disorder disease. Those affected appear normal at birth, but without treatment they develop severe psychomotor retardation. Throughout life, they must control their blood levels of phenylalanine (Phe) and consume a diet containing adequate amounts of Phe and tyrosine (Tyr). We have developed a liquid chromatographic/mass spectrometric (LC/MS) method for the quantitative evaluation of Phe and Tyr in food samples. This method takes advantage of the good separation of LC and the selective and reliable quantification provided by MS in the electrospray ionization mode. The LC/MS method is very suitable for the determination of selected amino acids in various matrixes. It is sensitive to levels as low as about 0.30 ppm for Tyr and 0.70 ppm for Phe and robust. Nearly 100 nondietary food samples were analyzed by the developed method.


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