Standard substance for nitrogen content determination (nitrogen standard sample)

Overview

The standard substance for nitrogen content determination (commonly known as nitrogen standard sample) is a key metrological standard to ensure the accuracy of total nitrogen content analysis in petrochemical products. This series of standard substances was developed by the Institute of Petrochemical Science and is specifically designed for analytical instruments that use chemiluminescence to determine nitrogen content. The product has good uniformity, stability, and accuracy of measurement, and is suitable for standard methods such as SH/T 0657, ASTM D4629 (light oil) and SH/T 0704, ASTM D5762 (heavy oil). It is a core reference material for laboratory quality control, instrument calibration, method validation, and capability assessment.

Technical specifications and concentration series

To meet the analysis needs of different matrix samples, this standard substance is divided into two series based on sample morphology and viscosity: "light oil" and "heavy oil", with concentrations ranging from trace to percentage levels

Light oil series

Suitable for nitrogen content analysis of naphtha, gasoline, kerosene, diesel, and other light distillate oils. The matrix is usually a light solvent such as toluene, xylene, or isooctane.

Concentration range: 0.2 mg/L to 1500 mg/L (ng/uL)

Standard concentration point:

Low concentration range: 0.2, 0.5, 1.0, 3.0, 5.0, 10.0 mg/L

Medium concentration range: 30.0, 50.0, 100, 200, 300 mg/L

High concentration range: 500, 700, 1000, 1500 mg/L

Heavy oil series

Suitable for nitrogen content analysis in heavy petroleum products such as crude oil, residue oil, wax oil, lubricating oil, and additives.

Concentration range: 5.0 mg/kg (ppm) to 5% (mass fraction)

Standard concentration point:

Ppm level: 5.0, 10.0, 50.0, 100, 300, 500 ppm

Percentage level: 0.10%, 0.3%, 0.50%, 1.0%, 2.0%, 3.0%, 5.0%

Note: The above concentration points can be selected according to actual needs.

Core selling points and application value

Developed with traceable measurement values

Developed and prepared by the Institute of Petrochemical Science, a domestic institution in the field of petroleum analysis, its measurement values are determined through strict balance calibration, purity analysis, and instrument comparison to ensure the accuracy and traceability of the test results.

Specially designed for chemiluminescence method

This product is specially designed for optimizing chemiluminescence nitrogen analyzer. This principle is based on high-temperature combustion to convert nitrogen oxides in the sample into nitric oxide, which then undergoes a chemiluminescence reaction with ozone for detection. The use of this standard sample can effectively eliminate matrix effects, ensure that the linear correlation coefficient of the standard curve reaches 0.999 or above, and significantly improve the detection accuracy of low content (such as<1 mg/L) samples.

Covering the entire concentration range, with good substrate compatibility

In response to the volatile nature of light oil and high viscosity of heavy oil, standard substances with different matrices were prepared separately, effectively avoiding injection errors caused by solvent evaporation or sample adhesion. The concentration points are densely set, and matching concentration points can be found for both trace nitrogen analysis of ultra-low sulfur clean fuels and high nitrogen content determination in crude oil.

Strict quality control, excellent stability

The product is packaged in dark ampoules or highly sealed sample bottles under dark conditions, and has passed the uniformity test and long-term stability tracking test. Storage conditions: Keep away from light. It is recommended to store in a cool and dry place. After opening, use once to prevent contamination and volatilization.

Usage recommendations

Instrument calibration: Use at least 3 different concentrations of standard samples (including blank) to draw a standard working curve.

Quality control: Insert a standard sample of known concentration into the test sample sequence as a quality control sample to verify the drift and repeatability of the instrument.

Daily verification: Regularly use intermediate concentration standard samples to verify the effectiveness of the standard curve.