Reduction of sample volume and waste generation in acid/base titrations using microelectrodes

The Analytical Development Section (ADS) has developed microelectrode methods for use with pH titrations and pH determinations. These microelectrode methods offer increased sensitivity and enable analyses to be done with smaller sample and buffer volumes than are used with standard size electrodes. This report establishes the technical validity of the methods and describes the application of these methods to decreased detection limits, decreased waste generation, and decreased radiation exposure

Low sample volume part-per billion level ion chromatographic analysis

ADS has developed an ion chromatographic method which enables low part-per-billion levels of analysis while minimizing liquid waste generation. This method incorporates several recent technical improvements in ion chromatographic instrumentation to achieve a ten- fold increase in sensitivity over existing ion chromatographic methods without additional analysis time or sample pre-concentration. This report outlines the method, establishes the precision and accuracy levels, and discusses the applicability of the method to waste minimization and radiation exposure reductio

Waste reduction and improved efficiency by ion chromatographic method modification

The Analytical Development group at the Savannah River Technology Center (SRTC) offers technical support to research programs in the laboratory as well as process control support for the rest of the Savannah River Site. This laboratory recently modified and upgraded their ion chromatography systems and methods to minimize waste generation and radiation exposure to employees. The following changes were made: conversion to a 1-point linear calibration from a 4-point quadratic calibration; replacement of chemical suppression system with an electrochemical suppression system; adjustment of hydroxide-based gradient elution protocol to improve separation of fluoride and formate and shorten experimental run; implementation of carbonate-based isocratic elution protocol; installation of lower capacity ion exchange columns which decrease analysis time by 50%; and adjustment of detector output to achieve a ten-fold increase in sensitivity. The combined changes decreased the analysis time by 90%, decreased the liquid waste generated by the laboratory by 95%, and lowered the detection limits by an order of magnitude

Reducing waste generation and radiation exposure by analytical method modification

The primary goal of an analytical support laboratory has traditionally been to provide accurate data in a timely and cost effective fashion. Added to this goal is now the need to provide the same high quality data while generating as little waste as possible. At the Savannah River Technology Center (SRTC), we have modified and reengineered several methods to decrease generated waste and hence reduce radiation exposure. These method changes involved improving detection limits (which decreased the amount of sample required for analysis), decreasing reaction and analysis time, decreasing the size of experimental set-ups, recycling spent solvent and reagents, and replacing some methods. These changes had the additional benefits of reducing employee radiation exposure and exposure to hazardous chemicals. In all cases, the precision, accuracy, and detection limits were equal to or better than the replaced method. Most of the changes required little or no expenditure of funds. This paper describes these changes and discusses some of their applications

Reclamation and reuse of freon in total petroleum hydrocarbon analyses

ADS is using a commercially available solvent reclamation system to recycle 95-97 percent of the Freon used in total petroleum hydrocarbon analyses. ADS has further developed the commercially available solvent reclamation system to accommodate radioactive contaminated Freon. This report establishes the following: validity of the method; success of recycling; and effect of radionuclides in recycling radioactive contaminated Freon. The standard analysis method for determining total petroleum hydrocarbons (commonly known as oil and grease determination) involves solvent extraction of the hydrocarbons using Freon followed by quantitation using infrared detection. This has been the method of choice because it is simple, rugged, inexpensive, and applicable to both solid and liquid samples and to radioactive samples. Due to its deleterious effect on the ozone layer, the use of Freon and other chloro-fluorocarbons (CFCs) has been greatly restricted. Freon has become very expensive (800$/liter) and will soon be unavailable entirely. Several methods have been proposed to replace the Freon extraction method. These methods include solid-phase extraction, solvent extraction, and supercritical fluid extraction all of which use gravimetric determination or infrared analysis of the extracted hydrocarbons. These methods are not as precise or as sensitive as the Freon extraction method, and a larger amount of sample is therefore required due to the decreased sensitivity. The solid phase extraction method cannot accommodate solid samples. Supercritical fluid extraction requires expensive instrumentation. ADS opted to keep the existing Freon method and recycle the solvent. An inexpensive solvent reclamation system was procured to reclaim the spent Freon. This reclaimer removes hydrocarbons from the Freon solvent by passage through an activated carbon bed

Reclamation and reuse of Freon in total petroleum hydrocarbon analyses

At the Savannah River Technology Center (SRTC), we have successfully demonstrated the use of a solvent recycling system to reclaim spent Freon solvent in total petroleum hydrocarbon (TPH) analyses of radioactive samples. A wide variety of sample types including ground water, organics, laboratory waste, process control, sludge, soils, and others are received by our lab for total petroleum hydrocarbon analysis. This paper demonstrates the successful use of a commercially available carbon bed recycle system which we modified to enable the recovery of 95-98 percent of the radioactive contaminated Freon. This system has been used successfully in our lab for the past three years