The relative error of flame atomic absorption spectrometry is less than 1%.

What are the advantages of atomic absorption spectrophotometry?

1. High sensitivity, low detection limit: flame atomic absorption spectrometry detection limit can reach 10-6 g L-1, non-flame atomic absorption detection limit can reach 10-9 g L-1.

2. High accuracy: the relative error of flame atomic absorption spectrometry is less than 1%, non-flame atomic absorption spectrometry is 3%-5%.

3. Good selectivity and little interference: Because different element lamp is chosen as radiation source when analyzing different elements, absorption is characteristic for this element.

4. Wide application: More than 70 kinds of elements can be determined by atomic absorption spectrophotometer manufacturers, including almost all metal elements and some kinds of metal elements (such as As, Se, Sb, etc.).

Advantage:

1. Atomization is carried out in a medium filled with inert protective gases and strongly reducible graphite, which is conducive to the decomposition of refractory oxides and has high atomization efficiency.

2, the sampling quantity is small, solid sample is 20 ~ 40ug, liquid sample is 5 ~ 10uL.

3. The effective residence time of ground state atoms in the determination area is long, almost all samples are absorbed, the sensitivity is increased by several orders of magnitude, and the absolute sensitivity can reach 10-14-10-9 G.

4. Excluding the action of the components often produced in chemical flame and flame components, reducing the chemical interference.

Shortcomings:

1, the interference of coexisting compounds is larger than that of flame method, and has strong background absorption and matrix effect.

2. Because the sampling quantity is small, the variation of the injection quantity and the position of the injection tube will lead to deviation, so the reproducibility is poor.

3, complex operation, high cost analysis.

1, the choice of analysis line:

The most suitable analytical line should be determined by experiments according to the specific circumstances.

Experimental method: First, the emission spectrum of hollow cathode lamp is scanned to find out which spectrum lines are available. Then, the sample solution is sprayed. According to the absorption, the spectrum lines which are not disturbed and the absorbance value is moderate are selected as the analysis lines.

2, the choice of slit width:

The appropriate width of the slit should also be determined by experiments, that is, the test liquid should be injected into the flame, the width of the slit should be adjusted, and the corresponding absorbance should be observed.

3, the choice of lamp current:

Under the condition of ensuring stable discharge and sufficient light intensity, low working current is selected as far as possible.

4. The choice of atomization conditions:

The flame type should be selected according to the ionization potential, atomization difficulty and redox property of the element under test.

Manufacturers of atomic absorption spectrophotometer