EAST AND WEST AA-7020 Atomic Absorption Spectrometer

EAST AND WEST AA-7020 Atomic Absorption Spectrometer

New Features

1. New and Improved Graphite Furnace

a) A newly designed rectangular-shaped furnace: with an innovative design, the cooling circulation system is leak-proof, as leaks may severely damage the graphite furnace. Consequently, the graphite tube's lifespan is greatly increased.

b) New replaceable graphite cones that can be used to quickly replace worn graphite cones while maintaining the electrode's conductive properties.

2. Improved Water Seal Monitoring and Alarm

A solenoid valve with a float switch will be used to control ignition. This prevents water shortages in the water seal caused by acetylene leaks, which improves the safety of the instrument.

3. Burner Heads Modifications

Burner heads willl automatically find the optimal flame height and improve the automation of the process.

4. Nitrous Oxide (Laughing Gas) System

A nitrous oxide system is integrated with the instrument's gas path, which increases the number of refractory elements that can be analyzed.

5. Graphite Furnance Dual Gas Path

Below 500 ℃: water is removed by burning the sample. Pure argon is added, but 5 to 10 % of the gases added will be pure oxygen. Some of the hydrocarbons will form CO2, which can effectively reduce interference and improve the accuracy of the analysis.

Above 500 ℃: automatically adds only pure argon to prevent any oxidation of the graphite tube, and thereby, extends the lifespan of the graphite tube.

6. Background Absorption and Background Correction

Improved background absorption and background correction software for more reliable and accurate results.

7. Optical Temperature Control

A optic temperature sensor is added to the graphite furnace atomize to improve the precision of the temperature control and heating rate.

8. New software features

a) Automatic remote ignition

b) Automatically calculates the final result

c) Setups sample enrichment injection

d) Manages ignition timing

e) Increased number of measurements: up to 100.

f) QA/QC Quality Control Parameters Setup

1) Implements SD in calculations

2) Implements RSD in calculations

3) Indentifies the correlation coefficient of the calibration curve

4) Uses QC samples for analysis

5) Implements baseline drift (with automatic sensitivity correction) in calculations

6) Unknown samples are automatically diluted (graphite furnace auto-sampler only)

9. Quality Control System

The slope of the calibration curve changes as the number of samples measured increases. At any time, during sample measurement, the standard solution can be measured and used for calibration curve correction. While improving measurement accuracy, this system makes compensating for measurement error easier.

10. Optional AA-7020 Graphite Furnace Auto-Sampler

Main Features

1. 2 Second Automatic Switching Between Flame and Graphite Furnace - Fulfilling International Standards

The flame and graphite furnace atomizer is installed onto the same platform ( patent number: ZL 2006 2 0023297.4). The graphite furnace and the element lamps are all installed with precise mechanical positioning. Additionally, all water, electrical, and gas paths are built into the instrument with equal precision. As such, it will only take 2 seconds for the automated switching of flame and graphite furnace atomizers. This greatly increases the convenience for the user from micro-analysis to trace analysis. Lastly, conversion to hydride generation will only take 1 minute. With these features, the instrument suffers less damage from switching between flame and graphite analysis, allowing for easier instrument maintenance.

2. Fast Peak Scanning - Fulfilling International Standards

Automatic slit selection; lamp current, automatic gain attenuation, and negative high voltage auto-balancing; and automatic wavelength scanning and positioning. All of which only take about 40 seconds to complete.

3. Flame/Graphite Furnace Atomizer and Graphite Furnace Power Supply Integrated in Main Unit - Meeting International Standards

The graphite furnace power supply is integrated with the main unit. Its small size and low power consumption (220V, power: 4kW). With no external power supply needed, the AA-7020 is one of the most compact AAS in the world (880 mm x 540 mm x 450 mm (L x W x H)). The graphite power supply is currently filing for a patent, (Patent No. ZL 2006 2 0,023,298.9).

4. Unique Suspension System for Optics System

The entire optics system is suspend upon a shockproof, heat insulated material on the optics base (Patent No.: ZL 2006 2 0023296.X). Mild external forces and ambient temperatures do not affect the instrument's stability. AA-7020 is a very useful analysis instrument for areas with poor laborartory conditions.

5. Graphite Tube Longitudinal Heating

Advanced, longitudinal heating technology increases the atomization temperature up to 3000 °C, fullfilling the temperature requirements of 2600 °C for trace analysis of Al, Ni, Pd, Sr, and other refractory elements. These standards fully comply with disease control and prevention provisions.

6. 1800 groves/mm Diffraction Grating for Higher Resolution and Higher Energy

China's first AAS to utilize C-T grating monochromator that has much higher resolution and sensitivity than a 1200 groves/mm monochromator.

7. Titanium Burner Head and Nebulizer

Die casted, titanium burner head and nebulizer are corrosion resistant, oxidation resistant, and able to withstand high temperatures and pressures for a longer working lifespan.

8. Flame/Graphite Furnace Background Correction

Unique background correction for samples with high salinity, such as soy sauce, for precise results

9. Automated, Reliable Safety Protection

Automated gas protection system: real-time monitoring of pressure, acetylene leakage, voltage, and possible fires and power failures. Also includes a variety of other safety measures.

Automated graphite furnace protection system: cooling water shortage alarms, gas pressure alarms and automatic shutdown system, and overheating and overcurrent protection.

10. Automation

Automated switching of atomizers, automatically identifies optimal ignition conditions, graphite furnace temperature control, and automated control of lamp selection, lamp current, gain, slit selection, and wavelength selection.

11. Short Optical Path

The instrument's dimension is only 880 x 540 x 480 mm (L x W x H) . With a shorter optical path, AA-7020 will be analyze As, Se, and other elements with sufficient energy and a low detection limit.

Technical Specifications

Optical System

Wavelength Range: 190 - 900 nm

Spectral Bandwidth: 0.1, 0.2, 0.4, 1.0, 2.0 nm, with 5 second automated switching

Monochromator: C-T grating monochromator

Grating: 1800 / mm

Wavelength Accuracy: ± 0.05 nm

Wavelength Repeatability: better than 0.05 nm

Blazed Wavelength: 250 nm

Resolution: better than 0.3 nm

Single beam, dual lens system

Light Source

1. Automatic Six Lamp Rotating Tower

Coded element lights with automatic positioning

Element Lamp Power Supply: 0 - 20 mA with automatic setting, self-correcting positioning,overcurrent protection, and warm-up process
Deuterium Lamp Power Supply: 0 - 200 mA automatic setting, self-balancing.

2. Baseline Stability
Static Baseline: ≤ ± 0.002A/30min, automatic baseline adjustment.
Dynamic Baseline: ≤ ± 0.003A/30min, automatic baseline drift adjustment.

3. Deuterium Lamp Background Correction:

Background correction for both flame and graphite furnace, can be corrected as 1 A background, correction factor of greater than 50 times.

Atomizer

1. Flame

a) Efficient glass atomizer, with an atomization efficiency of 38%, a 5 mg/Lcu solution can absorb up to 0.95 A.

b) Titanium nebulizer. Die casted, it is corrosion resistant, oxidation resistant, and able to withstand high temperatures and pressures.

c) Burner Heads: 50 mm and 100 mm interchange titanium burner heads, with precise vertical and rotational positioning.

d) Flame gas path undervoltage shutdown system, AVR, and gas (acetylene) leak shutdown system. Flame monitoring and safety system included.

2. Graphite Furnace


a) Temperature: Room temperature - 3000 ℃

Optimized graphite furnace structural design with advanced graphite tube longitudinal heating technology. It is able to maintain stable high temperatures in certain parts of the tube. Trace analysis of refractory elements, such as Al, Ni,Pd, and Sr can be easily conducted.

b) High precision injection. With good repeatability, injections are highly efficient with their low usage of power. Auto-sampler Injector RSD of 1 %.

c) Maximum injection volume of up to 70 μL, greatly increasing the previous maximum volume of 20μL.Samples with low concentrations can be analyzed as the instrument has a very low detection limit.

d) Temperature: Room temperature - 1000 ℃

From 1000 ℃ to 3000 ℃, the temperature is controlled by Optical Temperature Control. Precision 1 %. Reproducibility ≤ 0.5%.

e) Heating Rate: 2000 ° C/s

f) Cooling water shortages and low gas pressure alarms with automatic shutdown protection system. Also implemented with overheating and overcurrent protection.

g) Temperature programming of up to 20 steps. Heating modes: step, slope, and constant.

Detector

1. Japan's Hamamatsu R926 photomultiplier tube, wide range of spectral response with a low noise level. It is able to precisely monitor high voltages.

2. Stable high-intensity, long-lasting Hamamatsu's D2 lamp.

3. High-intensity, highly stable hollow cathode lamps (element lamps).

4. PC controlled instrument with signal processing.

Characteristic Element Data


Flame:

Cu Concentration: ≤ 0.02 μg/ml/1%
Detection limit: ≤ 0.003 ug/ml
Precision: 0.6 % RSD

Graphite Furnace:


Cd Quantity ≤ 0.3 × 10-12 g
Detection limit: ≤ 0.5 × 10-13 g
Precision: ≤ 1 % RSD

 

 

Automated Control System

1. Windows XP based software, which automatically controls instrument analysis parameters

2. Manages energy and voltage of instrument as well as element and D2 lamps.

3. One button functions: automatically selecting lamps, automatically setting slit and wavelength, determining lamp current and energy, and resetting energy to zero.

4. Automatic graphite furnace temperature control.

5. PC automatically determines and sets the optimal ignition conditions.

6. Instrument is fully automatic.

Data Processing

1. Signal processing: instantaenously, integral values of, peak height and peak area. Sampling time: 10 s. Integration time: 0-300 s, can be freely set.

2. Number of repeated measuresments: 1 - 20. Reading delay: 1- 100 seconds, automatically set.

3. Can hold up to 20 different samples' various calibration curves, which include linear and non-linear lines of fit and standard addition curves.

4. Scale adjustment: 0.1 - 100 folds, automatically set.

5. Reset function for single-point calibration.

6. Reports will be summarize calibration curves, analytical reports, single-element and multi-element analysis. AAS signal outputs, instrument conditions, and analysis paramaeters are automatically stored and printed.

Optional Graphite Furnance Auto-Sampler

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