Instrumentation at JR PETERS Lab
ICP IRIS Spectrometer
Phosphorus and Potassium Analysis by Spectrometer
P and K are determined by an ICP (inductively couple argon plasma) Spectrometer. This instrument measures P, K, Ca, Mg, Fe, Mn, B, Cu, Mo, Al, Na, S and Zn elemental concentrations by introducing the sample into the plasma by an aerosol spray. The aerosol spray passes through the plasma torch and causes the atoms to enter an excited state. When this happens, the atoms emit light at their characteristic wavelengths. The light transmitted at these wavelengths is recorded to identify the specific elemental concentrations based on intensity of the light source. We can detect P and K concentrations from 0.5% to 7.5% without a serial dilution (serial dilution increase concentration magnitude by six fold). However, we report any sample with less than 0.5% P or K as 0 and we automatically retest a sample with greater than 3.25% before the data is approved.
Skalar Wet Chemistry Analyzer
Skalar Wet Chemistry Instrument Principle of Operation
All media extracts, water, nutrient solutions, compost extracts and
fertilizers are analyzed for NH4, NO3, Urea-N and Chloride on the SAN plus Segmented Flow Analyzer by Skalar Inc. It is an automated segmented flow instrument to measure nutrient concentrations by a continuous flow method of wet chemistry analysis. In this method a stream of reagents and sample are segmented with air bubbles and pumped through a manifold to undergo treatment such as mixing, heating or dialysis before entering a flow cell to be detected. After detection, the reaction mixture is transferred to a waste receptacle. The measure signals are collected on a computer, where the data and peaks are processed.
C/N/S Analyzer
Nitrogen Analysis--Understanding Carlo Erba Nitrogen and Sulfur Instruments
Instruments are gas chromatographs, separating elements for analysis through a gas form. Meth
od is based on flash combustion: High temperature and injection of oxygen flow causes sample to become oxidized and combustion occurs, converting inorganic and organic samples into gas (and ash as a byproduct). Gases flow by carrier gas (helium), which is initially injected when auto sampler drops sample. Gases flow through copper (Cu) reduction tube, which reduces sulfur/nitrogen oxides to elemental nitrogen and sulfur. Gases flow into chromatographic column (GC column) inside furnace (metal-boxed area behind H2O trap) and are separated by thermal conductivity detector. This generates an electronic signal, reporting the concentration of nitrogen/sulfur found.
A graph is displayed and samples are calculated for quantitative analysis. Excess gases are released through vents:
M and R for carrier gas (helium) and O2 for oxygen.
Required Sample Amounts for Complete Analysis
| Sample Type |
Analysis |
Amount |
Dilution Factors |
| Tissue |
|
|
10x |
100x |
|
% N |
4-7 mg |
|
|
|
ICP Analysis |
0.5 g |
0.3 g |
0.2 g |
|
% S |
7-11 mg |
|
|
| Media |
|
|
|
|
|
ICP Analysis |
15 mL |
|
|
|
Skalar Analysis |
20 mL |
|
|
|
pH |
30 mL |
|
|
|
EC |
5 mL |
|
|
| Water |
|
|
|
|
|
ICP Analysis |
15 mL |
|
|
|
Skalar Analysis |
20 mL |
|
|
|
pH |
30 mL |
|
|
|
EC |
5 mL |
|
|
|
Alkalinity |
60 mL |
|
|
| Fertilizer Solution |
|
|
|
|
|
ICP Analysis |
15 mL |
|
|
|
Skalar Analysis |
20 mL |
|
|
|
pH |
30 mL |
|
|
|
EC |
5 mL |
|
|
|
Alkalinity |
60 mL |
|
|
| Dry Fertilizer |
|
|
|
|
|
ICP Analysis |
15 mL |
|
|
|
Skalar Analysis |
20 mL |
|
|
|
% N |
15 mg |
|
|
| What is... |
|
|
|
|
|
ICP Analysis |
15 mL |
|
|
|
Skalar Analysis |
20 mL |
|
|
|
% N |
15 mg |
|
|