title: Monitoring of enzymatic hydrolysis of penicillin G by pyrolysis-negative ion mass spectrometry.
abstract: A pyrolysis-negative ion mass spectrometry (Pyr-NIMS) is used for the monitoring of enzymatic hydrolysis of penicillin G (Pen G) to 6-aminopenicillanic acid (6-APA) and phenyl acetic acid (PAA). The high sensitivity and rapid response time of Pyr-NIMS allow its application to the simultaneously determination of these compounds. The mass to charge (m/z) values of 262, 156 and 135 of Pen G, 6-APA and PAA respectively, are used for the quantitative measurements by selected ion monitoring (SIM). The limit of detection (LOD), linearity and relative standard deviation (n=5) are 10 ng ml(-1), 100 ng ml(-1)-1000 mg ml(-1) and 1.5%, respectively The results are compared with high performance liquid chromatography (HPLC). An important advantage of the presented analytical system is the high linearity of signals without preliminary separation and recalibration. The main and interactive effects of pH, temperature and concentration of Pen G for enzymatic hydrolysis of Pen G are studied. Optimize conditions of pH (8), temperature (28 degrees C) and concentration of Pen G (12% w/v) in real samples are obtained.
authors.affiliation: Chemistry Research Center, Faulty of Science, Shahid Beheshti University, Evin, Tehran, Iran. aghassempour@scientist.com
authors.forename: Alireza
authors.initials: A
authors.lastname: Ghassempour
authors.forename: Farid
authors.initials: F
authors.lastname: Vaezi
authors.forename: Pooneh
authors.initials: P
authors.lastname: Salehpour
authors.forename: Mahnaz
authors.initials: M
authors.lastname: Nasiri-Aghdam
authors.forename: Massoud
authors.initials: M
authors.lastname: Adrangui
mesh_terms: D002851:Chromatography, High Pressure Liquid; D004800:Enzymes, Immobilized / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D013058:Mass Spectrometry; D010397:Penicillanic Acid / Q000031:analogs & derivatives / Q000032:analysis*; D010399:Penicillin Amidase / Q000378:metabolism; D010400:Penicillin G / Q000378:metabolism*; D010648:Phenylacetates / Q000032:analysis*; D013696:Temperature
chemical_list: D004800:Enzymes, Immobilized; D010648:Phenylacetates; D010397:Penicillanic Acid; D010399:Penicillin Amidase; C025136:phenylacetic acid; D010400:Penicillin G; C004408:aminopenicillanic acid