Graphite furnace atomic absorption spectroscopy

Graphite furnace atomic absorption is a method of atomic absorption analysis that uses graphite materials to make atomizers in the shape of tubes, cups, etc., and heats them with electric current for atomization.

Graphite furnace atomic absorption is a method of atomic absorption analysis that uses graphite materials to make atomizers in the shape of tubes, cups, etc., and heats them with electric current for atomization. Due to all samples participating in atomization and avoiding dilution of atomic concentration in flame gas, the analytical sensitivity has been significantly improved. This method is used for the determination of trace metal elements and has better performance than many other methods. It can be used for the analysis of small amounts of samples and direct analysis of solid samples. Therefore, its application fields are very extensive.

Graphite furnace atomic absorption spectrometer is one of the commonly used instruments for spectral analysis and is a conventional instrument for detecting metal elements. Using graphite furnace as an atomizer, it has high sensitivity, low sample consumption, and can detect elements at the level of 10-12 g/mL. It is widely used in trace analysis. To ensure the accuracy of the detection data, it is necessary to regularly maintain the graphite system.

The correct use of instruments and timely maintenance of instruments are effective ways to extend their lifespan and ensure their normal operation. Cleaning general workbenches and instrument exteriors with a cloth is necessary, and the following items cannot be ignored.

1. Automatic sampler section:

The low precision of the data reported by the graphite furnace is closely related to the small follow-up sample volume (10-30ul). The automatic sampler of this instrument (thermoelectric m6) mainly uses a principle similar to a syringe to suck and inject samples. If distilled water is used as the cleaning solution for the capillary tube all year round, it is inevitable that dust from the air will enter and accumulate at the bends of the pipeline. Over time, if you find that your automatic sampler experiences pressure delay during sampling or cleaning, it may be due to this reason. If not used for a long time, it may grow green moss. I chose to use dilute nitric acid for regular cleaning, but remember to clean the pipeline with distilled water after cleaning, because the syringe piston inside is made of metal, be careful of nitric acid corrosion.

2. Graphite furnace section:

Because it involves a cycle of heating, high temperature, and low temperature cooling, and there is also graphite with strong reducing properties that produces carbon deposits, as well as smoke generated during the ashing of different test substances, all of which will condense in the furnace or near the lens on the furnace path. If not cleaned for a long time, the light controlled temperature mirror at the bottom of the furnace may lose its temperature control ability due to the interference of carbon deposition, directly causing the graphite tube to burn out. The ashing material condenses on top of the lens, blocking part of the optical path and adding negative high pressure. Carbon deposition may occur during heating and Zeeman vibration, which indirectly increases the noise of the graphite furnace atomic absorption instrument.