Abstract
Diffusion methods previously developed for inorganic-N analysis of soil extracts were modified to improve reliability, increase the dynamic range, extend the scope of applications, and simplify the processing of samples for N-isotope analysis. In these methods, the soil extract is treated with MgO, or MgO plus Devarda‘s alloy, in a 473-ml (1-pint) wide-mouth Mason jar to convert NH4 +-N, NO3 –-N, and/or NO2 –-N to NH3-N. The NH3 thereby liberated is collected in H3BO3-indicator solution in a Petri dish suspended from the Mason-jar lid and determined quantitatively by acidimetric titration. With the modifications described, analyses can be performed on 10- to 100-ml samples of water, 0.5MK2SO4, 1MKCl, 2MKCl, or 4MKCl, at temperatures between 20 and 30°C. Recovery from 10 or 20ml was quantitative in 18–80h with up to 4mgN; recovery from 50 or 100ml was quantitative in 3–13 days with up to 2mgN. Removal of H3BO3 for N-isotope analysis by the Rittenberg process was effected using methanol. Mason-jar diffusion methods are much simpler and more convenient than conventional steam distillations. Comparative studies showed that quantitative determinations are more accurate and precise by diffusion than by distillation.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
