Basic Training 4th Annual ICP Conference

6:6 Container Transpiration

Summary of findings:

§ Transpiration occurs around the bottle opening and not through the bottle as previously thought. § Taping the bottle has no influence upon the transpiration rate. § Bottles that are partially full and opened periodically have the highest transpiration rate. § Opening the bottle periodically greatly increases the transpiration rate. § Smaller bottles transpire faster. § 30 ml bottles can not have a 1 year expiration date if certified to an uncertainty of = ±0.6 % relative. § Transpiration Controlled Technology™ (TCT) 1 totally eliminates transpiration

1. TCT - a patented technology that eliminates transpiration loss, greatly increasing a standard's shelf life. Developed by Inorganic Ventures for the optimal storage of standards after packaging.

7:1 Stability of elements at ppb concentra8on levels

Overview:

Consider the stability of acidic solu3ons of the elements. When looking at routes of instability, the trace analyst typically thinks of stability in connec3on with the concentra3on of the element. For example, when considering the stability of solu3ons at the part-per-million (ppm) concentra3on level, instability is generally caused by precipita3on forma3on or photo-reduc3on reac3ons. However, the main route of instability at the part-per-billion (ppb) level is derived from adsorp3on to the container walls. The stability of elemental solu3ons at the ppm level is more an issue of compa3bility and is addressed in detail in our Analy3cal Periodic Table. Plus, the stability of acidic elemental solu3ons is typically easy to achieve. It's difficult to imagine any route of instability for most elements. Take copper, for instance. Cu at the ppm concentra3on level in nitric acid is stable indefinitely. However, that same solu3on diluted down into the low to mid ppb concentra3on level makes the possibility of instability (caused by adsorp3on) a very real concern.