Total Nitrogen Analysis
Total Nitrogen (TN) stands for the sum parameter of all organic and inorganic nitrogen compounds. Trace levels (0.02 – 10.000 mg/kg or ppm by weight) of Total Nitrogen are measured with an elemental combustion analyzer according to Chemiluminescence detection technique. Total Nitrogen in fuels (NO2) pollutes the environment. It is corrosive to steel and poisons catalysts. Nitrogen compounds are more thermally stable compared to sulfur compounds and is often concentrated in heavier petroleum fractions and residues. Examples of Organic Nitrogen compounds that contribute to the Total Nitrogen number in petroleum products are Pyridines, Quinolines and Carbazoles. Common ASTM methods for nitrogen testing include: ASTM D4629, ASTM D5762, ASTM D7184, and D6069. The NEXIS TN total nitrogen analyzer provides a reliable and robust solution for labs.
Vacuum Gas Oils (VGOs) are the heavy oils left after petroleum distillation. VGOs have a viscous matrix and high boiling points. The EST Analytical TN 7000 has an injection port designed to maintain the injection port temperature at 500°C, while the autosampler tray can be fitted with a heater. These features aid in making the TN 7000 ideal for the examination of Total Nitrogen in VGO samples.
Crude oil is composed mainly of hydrocarbons mixed with a variation of nitrogen, sulfur and oxygen. The differences in the nitrogen, sulfur, and oxygen content can be attributed to where the crude oil originates. After drilling, crude oil is usually refined in order to create fuel, lubricants, etc. Due to the use of processing catalysts in the refining method, determining the nitrogen and sulfur content is very important. Trace amounts of sulfur and nitrogen can be very detrimental. Thus, determining the nitrogen and sulfur content is very important. This application will examine total sulfur and nitrogen in light hydrocarbon samples using the NEXIS combustion elemental analyzer, complete with a novel multilayer combustion tube.
EST Analytical has developed a new signal processing technique to achieve the lowest detection levels for trace level total sulfur and nitrogen for the NEXIS VP model Combustion analyzer. The NEXIS trace level sulfur, nitrogen and chlorine analyzer models equipped with the AS120 liquid/solids autosampler enables laboratories to perform a multiple point calibration line using ONE-Cal™ Technology and the NEXIS LINK software platform including Digital Signal Processing (DSP) Technology™.
This application note shows the analytical data and achieved LOD’s for both nitrogen and sulfur with the NEXIS VP model based on ISO ISO11843-2 methodology and the use of the NEN 7777 method which is incorporated in the NEXIS LINK operating software.
Nitrogen compounds can have detrimental effects on many environmental and industrial processes and are undesirable in finished products. This support the need and importance to monitor low level nitrogen concentration of various type of automotive fuels and related products. This Application Note shows the of the NEXIS VP model Total Nitrogen Analyzer for a set of gasoline and diesel fuel samples based on a 21-days trial to determine the precision of the nitrogen data in compliance to ASTM D4629 and DIN 51444 methods.
Labs around the globe share a common need to enhance lab productivty and stability when analyzing Total Sulfur, Nitrgen and Chlorine. Today, that process consumes too much time and money. When done improperly it can also contribute to poor data outcomes requiring labs to repeat calibrations and delay much needed sample analysis.
ASTM D5762 covers the determination of Total Nitrogen in liquid petroleum products and lubricants in concentrations ranging from about 40 to 10,000 mg/ kg.
Nitrogen compounds can have detrimental effects on many environmental and industrial processes and are undesirable in finished products. Nitrogen containing hydrocarbons seem to be the hardest to hydrotreat, meaning that the nitrogen content in the product of the hydrotreater is a measure of the effectiveness of the hydrotreating process.
This supports the need and importance to monitor trace level nitrogen concentration of various type of automotive fuels and related products. This Application Note shows the Total Nitrogen analysis performance of a set of liquid hydrocarbon samples, by the EST NEXIS model Total Nitrogen analyzer.
ASTM D4629 covers the determination of Total Nitrogen in concentrations ranging from about 0.3 to 100 mg/kg in liquid petroleum products having a boiling point range of 50˚C to 400˚C and viscosities between 0.2 and 10 mm²/s at ambient temperature. The ASTM D4629 standard is the preferred method in many countries to detect
and quantify total bounded nitrogen containing compounds in the various type of automotive fuels such as blended gasolines, diesel and synthetic oils.
Nitrogen compounds can have detrimental effects on many environmental and industrial processes and are undesirable in finished products. This supports the need and importance to monitor trace level nitrogen concentration of various type of automotive fuels and related products. This application note shows the total bounded nitrogen analysis performance of a set of liquid hydrocarbon samples, by the EST NEXIS Total Nitrogen analyzer.
The future requirements of Total Sulfur/Nitrogen analysis in light liquid hydrocarbons such like petrochemical base, intermediate and final products are heading towards very low concentration levels (ppb). This application note shows the precision, Level of Detection (LOD) and repeatability performance when a simultaneous analysis of Total Nitrogen and Sulfur is conducted using the NEXIS Combustion analyzer equiped with both ONE-Cal™ functionality and Digital Signal Prcoessing Technology (DSP). DSP Technology will enhance the Sulfur/Nitrogen detector performance resulting in a level of high sensitivity and repeatability.
This note shows the raw analytical calibration data and achieved LOD’s for both Nitrogen and Sulfur using the NEXIS model equipped with the AS120 liquids autosampler in the range of 0 – 1000 ppb.
ASTM D5762 is an established method for the determination of nitrogen in lubricating oils by oxidative boat inlet chemiluminescence technique. The application is of significant importance because nitrogen components can contaminate refinery catalysts. The determination of nitrogen concentration in lubricant oils is a measure of the total nitrogen in various additives. This application notes describes the principle of operation and obtained analysis results using the NEXIS TN analyzer model, which benefits the customer from ease-of-use, precise total nitrogen data en fast analysis times.
It is very challenging to analytically and precisely quantify Total Nitrogen concentrations less than 1 ppm in hydrocarbons such as liquid aromatics to be used for synthesis or to be used for various plastic polymerization processes. In order to analyze this kind of Ultra Trace level samples on day-to-day routine lab bases; repeatability with high accuracy and ease-of-use and excellent robust performance is highly required. EST has developed and validated the Ultra Trace Total Nitrogen ranges for the NEXIS and NEXIS VP model analyzers. Concentrations of below 1ppm defined as Ultra Trace Nitrogen are no longer a challenge.
The developed functionalities ONE-Cal™ and DSP Technology™ are made available for everyone and this data demonstrates high sensitivities, repeatabilities and linearities of the Ultra Trace Levels in quantifying Total Nitrogen using the EST NEXIS VP model. The use of the DSP Technology™ which improves the signal to noise ratio on both sides of the equation has been applied to the NEXIS and NEXIS VP. A comparison is made between the DSP function running disabled and enabled and is carried out for specifically in the Ultra Trace regime of the calibration region. The data gained by this comparison can be obtained in this Application Note.
The oxidative combustion analysis of a wide range of petroleum samples which may contain high sulfur and/or nitrogen content may result into potential carry-over effect issues that can result in downtime for this analysis. The EST NEXIS VP model with AS120 liquid autosampler uses a direct injection technique combined with a high efficiency combustion tube design to avoid the risk of incomplete combustion and therefore demonstrates a very low carry-over effect. This application note describes the practical lab study for the “carry-over effect” and the degree to which the NEXIS VP TN/TS elemental combustion analyzer manages1) the “carry-over” effects which is based on a reference definition. Extreme high sulfur/nitrogen concentrations of 10,000 ppm as well as middle high ppm concentrations 100 ppm of nitrogen and sulfur samples were analyzed multiple times and multiple sets followed by a set of blank solvent injections to determine the “carry-over” effects.
Quantifying accurately high concentrations of Total Nitrogen in liquid hydrocarbons and solid samples with a Combustion analyzer is dependent on the controlled combustion process and the linearity of the Chemiluminescence detector (CLD). The NEXIS and NEXIS VP models Total Nitrogen analyzer has applications in a wide range of petroleum products including lubricants, resins and a variety of polymer sample types. Normally high range calibration lines show a second order line, which can have a negative impact on the accuracy of the obtained nitrogen test data. This Application Note shows the performance of the NEXIS product at a wide linear working range, without the need to change from typical PMT settings of the CLD detector or the need to perform separate calibration lines.