Operation
This blog will detail the proper maintenance of Gas diffusion membranes. There are various approaches, some labs replace their membrane daily preferring to avoid the issue altogether while others may go weeks or even months using one membrane with no issues. So, what is the right approach? Unfortunately, there is no definitive answer as there [...]
This post is designed to offer assistance to users of cadmium coils in the analysis of Nitrate. Since the use of the cadmium coil is fairly complicated and because there are many possible applications, we want to discuss the different sizes that are available as well as the advantages of the various sizes. Cadmium coils [...]
Old Surfactant Solution Causes Problems in Cadmium Reduction Coils In our earlier blog posts we have discussed many reasons for possible loss of cadmium coil reduction efficiency. Along with metal contamination, nitrate contamination and gas contamination, we have also seen old surfactant solution cause problems in cadmium reduction coils. Because of the unstable nature of [...]
Last week, we discussed the loss of reduction efficiency in cadmium coils caused by nitrate contamination in ammonium chloride. This week we are examining metal contamination and cadmium coil efficiency. This type of contamination occurs in the sulfanilamide solution. Of course, sulfanilamide solution contains N-naphthylethylenediamine dihydrochloride which serves to bind heavy metals. If metal exists [...]
Nitrate Contamination: A very real and very well documented effect in various laboratories is the loss of reduction efficiency in cadmium coils caused by nitrate contamination in the ammonium chloride. Nitrate contamination will cause a steady continuous reaction in a cadmium reduction coil during a run. Depending on the level of contamination, this condition can [...]
Two things to consider when using a cadmium coil in a segmented flow analysis system: Pure gas & checking the system for leaks. Pure gas is vital when it comes to the cadmium coil, any impurities in the gas or leaks in the SFA system itself will significantly reduce a cadmium coil's reductive efficiency. In [...]
Get the most life out of your cadmium reduction coil... The Proper Technique to Activate a Cadmium Reduction Coil In order to create a good copper complex it is important to use acid to clean and prepare the surface of the cadmium. Cadmium is very susceptible to destruction if the acid concentration is too high [...]
Further Discussions Our last blog post about how much better Teflon is than glass resulted in extensive responses from many different users. Some users were in agreement, some were thankful for the facts regarding how much better the physical properties of Teflon are over glass and others were somewhat confused. The main confusion has to [...]
- And the Science behind It Years ago when I started working with autoanalyzers, glass was the most common material used to transport and mix fluids and I dutifully learned the art of working with very expensive and easily snapped fragile mixing coils and glass fittings. At the time I was told that glass had [...]
The U.S. EPA and ASTM cyanide analysis methods based upon gas diffusion amperometry do not require a preliminary acid distillation step and are now approved as amendments to 40 CFR 136 Clean Water Act Methods on their website as published in the 2012 Method Update Rules (MUR) in the Federal Register. These methods were specifically [...]
