Page 7 - Shimadzu AA-7000

Advantages of the Double-Beam System
Long-term stability High sensitivity
A
The graph shows the results of The graph shows the direct b s
measurements on 2 ppm copper (Cu) measurement results for 0.1
conducted over at least one hour. Absorbance ppm lead (Pb).
(The plot shows mean values for 11
repeated measurements.) Over the
course of more than 600
measurements, the instrument Measurement time Conc(ppm)
achieved a relative standard Data Showing Long-Term Stability for 0.1 ppm to 0.4 ppm Calibration Curve for Lead (Pb)
Flame Cu Measurements
deviation within 1%.
Support for Developing Analytical Conditions
Automatic gas flow rate optimization
Automatic searching for optimal fuel gas flow rate (Japanese Patent 2099886). It is important
to determine the optimal gas flow rate for the flame when using an organic solvent or after
changing the burner height. The AA-7000F Series automatically optimizes the gas flow rate
by measuring the changes in absorbance between a blank and a standard sample. The
difference between the two is displayed on the screen. The gas flow rate achieving the
highest sensitivity is detected and this value is automatically set as the gas flow rate value.
Automatic burner height optimization (AA-7000F/AAC)
The absorption sensitivity for flame analysis is also affected by the burner height. This results
from variations in the flame temperature due to the burner height. The flame temperature is
also affected by the matrix components. AA-7000F/AAC adjusts the burner height in 0.5 mm
steps to automatically search for the optimal conditions.
AA-7000F enables above function by AAC-7000 (option).
Optional Autosampler Reduces Analysis Workload

Low carryover
Great care must be taken to avoid carryover during flame analysis. The new ASC-7000
autosampler rinses the nozzle at the rinsing port on the overflow mechanism after each Discharge
-4
sample measurement is complete. This ensures 10 max. carryover during the
measurements of multiple samples. The graph shows the results of consecutive analyses
of 10 ppm, 20 ppm, and 50 ppm sodium (Na) standard solutions in the EMISSION mode.
No carryover could be detected when measuring the 10 ppm standard sample
immediately after the measuring the 50 ppm Na standard sample. Conventional method Overflow method Data showing low carryover

Trace Sample Analysis Using Micro Sampling
Micro sampling
At least 1 mL (1000 µL) volume of a liquid sample is required for the continuous intake of
sample during normal flame analysis. With micro sampling, however, approximately 50 to 90 Sampling port Sampling port
µL of sample is injected in one shot into the flame and quantitation is based on the height
and area of the peak signal obtained. This method offers the advantages below.
Advantages Solenoid Solenoid
valve
valve
(closed) (opened)
. Permits analysis of small sample volumes
. Multi-element analysis of small sample volumes 1. Sample injected into 2. Solenoid valve opens to inject sample
micro sampling port. in one shot into the flame.
. No blockage of burner slot with samples having a high salt concentration
. Synchronized with the autosampler for auto-dilution measurements
* Synchronization with the autosampler requires the optional micro sampling kit.
Example of micro sampling analysis
Examples of the measured waveforms (overlaid) and calibration curve for micro
sampling analysis are shown to the right.
A 2-ppm Cu standard solution was prepared by auto-dilution using the autosampler.
The autosampler can also be used to conduct dilution measurements of the sample.
(Injection volume: 90 µL)

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