title: Improvement of sensitivity of electrolyte cathode discharge atomic emission spectrometry (ELCAD-AES) for mercury using acetic acid medium.
abstract: A method has been developed to improve the sensitivity of the electrolyte cathode discharge atomic emission spectrometry (ELCAD-AES) for mercury determination. Effects of various low molecular weight organic solvents at different volume percentages as well as at different acid molarities on the mercury signal were investigated using ELCAD-AES. The addition of few percent of organic solvent, acetic acid produced significant enhancement in mercury signal. Acetic acid of 5% (v/v) with the 0.2M acidity has been found to give 500% enhancement for mercury signal in flow injection mode. Under the optimized parameters the repeatability, expressed as the percentage relative standard deviation of spectral peak area for mercury with 5% acetic acid was found to be 10% for acid blank solution and 5% for 20 ng/mL mercury standard based on multiple measurements with a multiple sample loading in flow injection mode. Limit of detection of this method was determined to be 2 ng/mL for inorganic mercury. The proposed method has been validated by determining mercury in certified reference materials, Tuna fish (IAEA-350) and Aquatic plant (BCR-060). Accuracy of the method for the mercury determination in the reference materials has been found to be between 3.5% and 5.9%. This study enhances the utility of ELCAD-AES for various types of biological and environmental materials to quantify total mercury at very low levels.
authors.affiliation: National Centre for Compositional Characterisation of Materials (CCCM), B.A.R.C., ECIL (P.O.), Hyderbad 500062, India. shekhar raparthi@rediffmail.com
authors.forename: R
authors.initials: R
authors.lastname: Shekhar
mesh_terms: D019342:Acetic Acid / Q000737:chemistry*; D000818:Animals; D004566:Electrodes; D004573:Electrolytes / Q000737:chemistry*; D017022:Flow Injection Analysis; D008628:Mercury / Q000032:analysis* / Q000737:chemistry; D012015:Reference Standards; D012997:Solvents / Q000737:chemistry; D013054:Spectrophotometry, Atomic / Q000295:instrumentation / Q000379:methods* / Q000592:standards
chemical_list: D004573:Electrolytes; D012997:Solvents; D008628:Mercury; D019342:Acetic Acid