title: Experimental design optimization for electrochemical removal of gentamicin: toxicity evaluation and degradation pathway.
abstract: Electrochemical degradation of gentamicin was achieved using a laboratory scale electrochemical reactor by optimizing pH, current density and treatment time. A two step statistical optimization was performed as per factorial design and center composite design (CCD). A Pareto chart was used for selecting statistically significant effects and an analysis of variance (ANOVA) table indicated significant curvature. Thus adding additional experimental runs improved the model fitting through a second order model. Maximum degradation was predicted at a pH of 6.7, 70 A m(-2) and 45 min. The experimental data fitted well through a reduced quadratic model with R(2) equal to 0.945. The toxicity of degradation products as determined by disc diffusion assay employing Pseudomonas aeruginosa strain was found to be reduced by 55%. The degradation pathway of gentamicin was studied using mass spectral (MS) analysis. Pure gentamicin showed a molecular ion peak at m/z 478 ([M + 1](+)), and after addition of NaCl as electrolyte, the mass peak was observed at m/z 523. After 15 min of electrochemical treatment, a new peak appeared at m/z 316 due to the loss of one pyran moiety. After 45 min of electrochemical treatment, another peak appeared at m/z of 478 due to loss of two Na(+) from gentamicin.
authors: Department of Pharmaceutical Sciences, Guru Nanak Dev University, Amritsar, Punjab, India.
authors: Radhey S
authors: RS
authors: Dhuria
authors: Rajbir
authors: R
authors: Bhatti
authors: Manpreet S
authors: MS
authors: Bhatti
authors: Palwinder
authors: P
authors: Singh
authors: Patrick J
authors: PJ
authors: Whitcomb
authors: Ashwani K
authors: AK
authors: Thukral
mesh_terms: D000704:Analysis of Variance; D000900:Anti-Bacterial Agents / Q000302:isolation & purification* / Q000378:metabolism / Q000633:toxicity; D055664:Electrochemical Techniques; D005839:Gentamicins / Q000302:isolation & purification* / Q000378:metabolism / Q000633:toxicity; D011550:Pseudomonas aeruginosa / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D000900:Anti-Bacterial Agents; D005839:Gentamicins