Modern multi-nutrient fertilizers produced for home and agricultural use are formulated from multiple sources to provide significant amount of nitrogen, phosphorus and potassium, the major plant nutrients, and lesser or even trace amounts of other nutrients needed by different crops, such as boron, calcium, iron and zinc.
Until relatively recently, fertilizers were tested and certified for their nutrient content, but little attention was paid to the possibility of heavy metal contaminants introduced by the mineral sources used to prepare the fertilizer. However, in response to incidents of heavy metal contamination of cropland, several states have enacted regulations in the past seven years that limit the amounts of some potentially hazardous non-nutritive elements in fertilizers. Several countries, including Japan, China, and Australia, and the European Union, also limit the amount of selected elements in fertilizers.
While fertilizer manufacturers and state regulatory authorities have needed to develop analytical methods to implement these regulations, until now there have been no certified reference materials available that they could use to validate the accuracy of their measurements. It can be difficult to measure accurately trace levels of some metals in a chemically complex mixture like fertilizer.
NIST's Standard Reference Material, SRM 695, "Trace Elements in Multi-Nutrient Fertilizer," was developed in collaboration with members of the Association of American Plant Food Control Officials (AAPFCO) and The Fertilizer Institute (TFI) to help meet this need. SRM 695 is a typical multi-nutrient fertilizer certified for the content of both major elements and trace elements, including calcium, iron, magnesium, manganese, sodium, potassium, zinc, arsenic cadmium, chromium, cobalt, copper, mercury, molybdenum, nickel, lead and vanadium. Additional reference values are provided for aluminum, boron, nitrogen, phosphorous and selenium.
Epoxy compound gets a graphene bump
14.11.2018 | Rice University
Automated adhesive film placement and stringer integration for aircraft manufacture
15.11.2018 | Fraunhofer IFAM
Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.
Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure
Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...
09.11.2018 | Event News
06.11.2018 | Event News
23.10.2018 | Event News
16.11.2018 | Health and Medicine
16.11.2018 | Life Sciences
16.11.2018 | Life Sciences