الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Antimicrobial drugs are chemicals used to prevent and treat microbial infections. Antimicrobial drugs can be classified as antibacterial, antifungal, antiviral, or antiparasitic depending on the type of microbe the drug targets. They can be classified according to their effects on target cells (bactericidal & bacteriostatic), their spectrum (narrow, moderate & broad) and nature (natural, semi-synthetic & synthetic). In microbiological assay, an antibiotic concentration is determined from the microbiologic response of a strain of test organism to a series of standard antibiotic concentrations. They are based on agar diffusion methods. The assays measure the total antimicrobial activity in the specimen to which the indicator organism responds. Chemical assays are based on reactions that involve specific chemical groups on antibiotic molecules so, the concentrations of antibiotics is determined by many chemical assays include active drugs as well as metabolic breakdown products that retain the reacting moiety. Using the HPLC technique, highly reproducible, difficult separations are achieved rapidly and quantitatively. The majority of HPLC separations are accomplished in less than 1 hour, with many requiring only a few minutes Mass spectrometer is capable of analyzing charged particle based on their mass. A typical mass spectrometer consists of an inlet system, which supplies the pure compound (separated from complex biological matrix by GC or HPLC) to the mass spectrometer, an ion source, a mass analyzer, and a detector. NMR spectroscopy is an extremely powerful tool to measure levels of metabolites in various body fluids, e.g. urine, bile, blood, or plasma, as well as to elucidate unknown metabolites and metabolism pathways. However, the NMR method suffers from the drawback that the analyte must be present at a concentration of 50 mM in the sample.