The new AA-6300 is a double beam atomic absorption spectrometer for full automatic multi element analysis in flame and furnace operation and rounds off the Shimadzu AAS family from the smallest AAS in its class (AA-6200) up to the AA-6800 with fullautomatic change of the atomization unit.
The system operates in the wavelength range from 185-900 nm and includes a monochromator in Czerny Turner mounting with a holographic grating (1800 lines/mm). The detector system consists of a photomultiplier for the range from 185-600 nm and a Si detector from 600-900 nm and provides a maximum performance especially for the determination of ultra traces of elements. The optical double beam system guarantees longtime stability even in high temperature flame conditions.
An important factor for overnight multielement sequences is the availability of light sources, so it is possible to plug in to the lamp turret up to six hollow cathode lamps, which allows in case of multielement cathodes up to 20 elements in one analytical run. The full automatic lamp turret with an intelligent lamp preheating function allows the lamps to be stabilized just in time before the analysis starts.
The optical bench of the flame version includes a full automatic safety gas control box and allows the optimized element specific flame composition resulting in a maximum of flame sensitivity. Additionally it is possible to prepare an automatic burner positioning in order to provide the most appropriate hardware conditioning for each target element.
For an accurate determination of trace elements in samples with complex matrix the system includes two methods of background compensation in flame and furnace mode as a standard feature. First of all the deuterium method for compensation of spectral interferences caused by molecular absorption and particulate caused scattering and additionally the high speed self reversal (Smith-Hieftje) method, which allows the compensation of absorption line overlapping as well as structured background.
Excellent performance and highest reliability have been proven in thousands of Shimadzu AAS all over the world. The new AA-6300 in flame operation uses a titanium burner head, ceramics impact bead, platin / iridium capillary and a sophisticated spray chamber made of polypropylene which is resistant against all solvents such as strong acids or organic solutions used in atomic absorption spectroscopy. The high efficiency nebulization unit in combination with a stable double beam optical system results in such excellent performance data as 0.350 Abs. for a 2 ppm copper solution and a detection limit of 0.0015 mg/l.
With all these features the system is ready for operation whichever sample should be analyzed, aqueous solutions or organic solvents in the concentration range of % down to µg/l. The optimization of all system parameters takes care on maximum energy and highest sensitivity, that means with an automatic flame optimization or burner positioning function the instrument meets every sample.
The quantitation of multielements in ultra trace concentration levels is done on the AA-6300 in combination with a digital controlled Graphite furnace GFA-EX7. In this combination the instruments works on a maximum energy level and electronics double beam stability. The digital furnace with high sensitivity and intelligent temperature control results in detection limits (acc. to DIN 51401/1)which are almost out of imagination. The detection limit for lead in furnace measured according to 3 sigma is 0,085 µg/L using an injection volume of 20 µL, resulting in an absolute value of 1,7 pg. Furthermore this furnace concept guarantees extremely long graphite tube lifetimes (2000 shots at 2800 °C and an HNO3 acid concentration of 0,1 % in aqueous solution). Table 1 shows typical detection limits of elements in graphite furnace operation using an injection volume of 20 µL.
In combination with the sample preparation station ASC-6100 and the dilution system ASK-6100 the AA-6300 spectrometers in flame and furnace allows the fullautomatic multi element analysis of up to 20 elements in one analytical sequence. The preparation of calibration curves is done automatically from only one stock standard solution, samples exceeding the calibration range are diluted and reanalyzed. This function is available in furnace and flame (microsampling).
The hardware concept is modular and available for the entire AAS family. The introduction of AA-6300 is done simultaneously with the latest version of our user friendly WizAArd software (32- bit structure), under windows 2000 environment. The software allows the preparation of new methods using wizard function, means defined keys which guides the user through the entire menue, in order to prevent any misoperation. On the other hand it is possible for the experienced user to control the system via worksheets and do any optimization of system parameters individually.
The software package includes many features in the field of QA/QC such as calibration check, quality control standards, spikes and more. Additionally optimization functions in flame and furnace operation are available in order to find out the most appropriate element parameters.
This version of software is compatible with all requirements of CFR 21 part 11 (electronic signature) and FDA regulations. Important for the use of atomic absorption spectrometers as tools in quality control and certified laboratories is a validation program which is included in the WizAArd software as a standard.