Nitrogen and Other Elements in Plant Material

By Atlantic Microlab

Finding a competent laboratory to perform percent-by-weight determinations of Nitrogen in plant material, fertilizer, or even soil can be a challenge for any company working in the arena of Botany, Horticulture, or Agronomy. Atlantic Microlab takes the hassle out of procuring quality results by offering over 50 years of experience in doing assays for industries and academia, ranging from biotech and pharmaceuticals to material sciences and agriculture.

Using the modified Pregl method for Carbon and Hydrogen and the modified Dumas method for Nitrogen, Atlantic Microlab is an industry leader in elemental analyses. Samples requesting Nitrogen determinations are combusted in an Oxygen-rich environment to form Oxides of Nitrogen. The mixture passes through copper maintained at a temperature around 700 degrees Celsius to yield N2. The Nitrogen gas flows through a chromatographic column and the resulting peak is detected by thermal conductivity from which the Nitrogen percentage is easily integrated and calculated.

Atlantic Microlab has found that using the robust Carlo Erba 1108 instrument is a terrific choice for this particular assay. Ultra-high purity Helium acts as the carrier gas and mixes with UHP Oxygen dosed into the system during the combustion interval. Dynamic Flash Combustion occurs at a furnace temperature setting of approximately 1000 degrees Celsius in the presence of oxidizing catalysts such as Chromium Oxide, Copper Oxide, and Tungsten Anhydride. Using tin combustion capsules spiked with Vanadium Pentoxide provides further Oxygen and raises the combustion temperature to nearly 1400 degrees Celsius, ensuring complete combustion of practically any plant material. All samples are weighed on microbalances such as Mettler, Perkin Elmer, or Sartorius—industry leaders in high precision weighing instruments. Analyzers and balances are calibrated daily, and calibrations are rechecked at frequent intervals during any analysis period.

What’s even better news is that dry and reasonably homogenized samples weighing as little as 5 mg can be analyzed quickly, efficiently, and cost effectively, allowing Atlantic Microlab to achieve detection at levels as low as 0.05%!

Exploring the company’s website will display the ease at which a client can find and access submittal forms (the essential directions for all analyses). Also offered is a handy color-coded guide explaining how to properly complete the form which accompanies all samples upon submission. The FAQ section covers nearly any inquiry a customer might have including sample size requirements for all tests, how analyzing isotopes are detected by the instrumentation, detection limits, and more. But our staff is cheerfully available by phone or email to answer any particulars about individual samples.

If turnaround time is a concern, Atlantic Microlab has a reputation for being speedy, accurate, and affordable…a combination of attributes that can be difficult to find in the analytical industry. Samples are normally completed within 1 to 3 days. For an additional $21 charge per sample, RUSH analysis is provided for up to 10 analyses per submission. Results for RUSH requests are emailed or faxed by 5 pm on the day they are received.

Are other elements of concern? Atlantic Microlab has specialized in elemental analysis for Sulfur, Carbon, Hydrogen, and all of the Halogens for 54 years! Perhaps analyzing Sulfur is of interest. The analysis is done similarly to Nitrogen and results can be obtained in as little as 5 minutes. Sulfur samples are weighed on the aforementioned microbalances and combusted in an Oxygen rich atmosphere using the same tin capsules along with a Vanadium Pentoxide additive. Oxides of Sulfur are formed during the burning process and reduced to SO2 when passed over hot copper. The Sulfur Dioxide peak is detected by thermal conductivity after passing through a robust chromatographic column, and results are imminently available using the slick EAGER 300 software in tandem with the Carlo Erba 1108 instrument. Like Nitrogen, Sulfur results can be obtained as low as 0.05% without interference from such elements like Sodium, Potassium, Lithium, Boron, or Copper as is sometimes the case with other methods.

Maybe Carbon/Nitrogen ratios are of interest. Analyzing Carbon and Hydrogen has been Atlantic Microlab’s bread and butter since our inception. While most of our analyses in the past for C&H have been geared toward the pharmaceutical, biotech, and medicinal chemistry sector, we have developed methods recently to handle numerous materials, including plant and soil. As with anything, the drier and more homogenized the samples are, the better the results…and we don’t need jars or buckets of material—usually only 30-40 milligrams will suffice!

Clearly, researchers seeking quality analyses are in good hands with Atlantic Microlab. Founded in 1969 by Eli Lilly Chemists Alfred and Karen Brown, the lab has been family owned and operated from the beginning. Al’s son, Patrick, grew up working in the lab while attending high school and continued his tutelage in the lab as he pursued his education in Chemistry at Georgia State University. Patrick has managed the lab since 1992 and took over ownership in 1997. He still is active in the lab analyzing and evaluating the data on a daily basis, while grooming his twenty-five-year-old son, Logan, who has worked in the lab for nearly 7 years, displaying both the necessary passion and competency to one day take the helm of the business. So when the time for needing a reputable company with over a half century of experience doing elemental analyses commences, researchers can be confident in Atlantic Microlab providing fast, affordable, and most importantly, reliable service! Give us a call or shoot us an email to see what our lab can do for you!