there are various methods for the analysis of potassium sorbate and sodium benzoate in food products, but a rapid and reliable method for identification of these preservatives in doogh (an iranian traditional dairy drink) is a procedure, in which high performance liquid chromatography (hplc) utilized and followed by uv diode array detection of the two preservatives. the aim of this case study w...

IntroductIon Protein samples of biological origin can be very complex, and require powerful separation tools like multidimensional liquid chromatography (MDLC) to resolve components of interest. MDLC can be performed using on-line and off-line approaches. In the off-line MDLC approach, due to a fractionation step, a high flexibility in terms of column dimensions, optimization of flow rate, buff...

CLINICAL CHEMISTRY, Vol. 26, No. 6, 1980 789 interference with analysis for theophylline by high-performance liquid chromatography. Clin. Chem. 24, 1847 (1978). Letter. 4. Kelly, R. C. Prentice, D. E., and Hearne, G. M., Cephalosporin antibiotics interfere with the analysis for theophylline by highpressure liquid chromatography. Clin. Chem. 24, 838 (1978). Letter. 5. Orcutt, J. S., Kozak, P. P....

We present procedures for determining theophylline in 50 mul of serum. The drug is extracted into a small volume of solvent that contains an internal standard, 8-chlorotheophylline. The extract is Analyzed by isocratic reversedphase chromatography, with measurement of eluted theophylline at 273 nm. Day-to-day reproducibility within 5% is attainable for the concentration range 5--20 mg/liter. Ot...

Amphibians have a large variety of antimicrobial peptides that serve as natural innate barriers limiting microbial infection or, in some instances, act as an integral component in response to inflammation or microbial infection. A novel peptide with antibacterial effects and without hemolytic activity was purified from skin secretions of Rana ridibunda by multisteps cation-exchange FPLC, revers...

K-27 and K-48, bisquaternary pyridinium aldoximes differing only in the number of methyl units in the alkyl bridges between the two quaternary nitrogen atoms, are promising candidates for use as potent and effective antidotes to organophosphate intoxication. K-27 and K-48 were treated with rat hepatic microsomal preparations from healthy (control) and diabetic animals. Microsomal metabolism was...

Tandem mass spectrometry was used to identify naturally processed peptides bound to major histocompatibility complex (MHC) I and MHC II molecules in central nervous system (CNS) of eight patients with multiple sclerosis (MS). MHC molecules were purified from autopsy CNS material by immunoaffinity chromatography with monoclonal antibody directed against HLA-A, -B, -C, and -DR. Subsequently pepti...

The retention parameters of seven monoand nine ditetrazolium salts were investigated by reversed-phase liquid chromatography (RP-LC) using polyethylene-coated alumina support with various concentration of eluent-mixtures and by reversedphase thin-layer chromatography (RP-TLC) using the same support and eluent-mixtures. Principal component analysis (PCA) followed by non-linear mapping (NLM) and ...

IN T RO DU C T IO N Metformin hydrochloride is an anti-diabetic drug typically administered orally while treating non-insulin dependant (type 2) diabetes mellitus.1 It is one of the most widely-used oral antidiabetic drugs worldwide, with over 48 million generic formulation prescriptions filled in the United States alone.2 Liquid chromatographic analysis of metformin and related impurities pres...