2435 - Potentiometric Stripping Analyser

Potentiometric Stripping Analyser – High Sensitivity Tracescan

2435Model 2435 includes in a compact cabinet a the control unit, the cell system and an automatic burette.
The control unit is a high precision current source to control the mercury layer formation at the working electrode surface, a fast high impedance electrometer to read the Potential variations at the reference electrode, a high-speed 12-bit A/D converter to sample the analog potential signal and to convert it into numeric data a microprocessor control unit providing the general management and the proper interface for external Personal Computer.
The top section of the cell is provided with five standard NS6 conical holes for Reference, Counter, and Working electrodes, an optional pH electrode (sometime required to check the solution pH before starting the analysis) and the injection port for both the sample and standard additions. A standard NS 12 conical hole is provided for the propeller stirrer. The stand allows to use standard polarographic cells (both Pyrex or Teflon®). The purging system is built-in with provision for both direct bubbling into the solution and surface blanketing: the switching between stand and control unit is accomplished automatically under microprocessor control.
The automatic burette is composes by a 1000ml glass syringe fitted with a 3-ways valve and motor of 48000 step. The burette allows automatic adds of minimum 50ml of sample with a precision of +0.02ul.

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Main features:

2435 buret•    High Sensitivity: down to ppb level
•    Some common metals detected simultaneously

  • No sample digestion or preparation required in most cases
  • Minimum sample quantity required
  • Extremely fast results
  • Fully automated operation
  • Extremely compact system
  • Battery operating option for in field analysis

Detection of heavy metals and pollutant substances has become a crucial task in environmental surveillance. Many users, even not skilled in chemical job, are now requested to keep under control parameters of heavy metals and other pollutant compounds resulting from their specific ativity.
The AMEL Tracescan system is a complete, powerful instrument capable to perform trace metal detection in several matrices such as: water (clear, sea, waste, drinking, etc.) with great case even for users not skilled in chemical problems.
The operation is simple and completely computer-aided by means of clear screen menus. The operator is just requested to put his sample into the analysis cell along with a small quantity of supporting electrolyte and to follow the simple menu instructions: all the analysis steps will be performed automatically without any further operator's intervention and the numeric result (directly in concentration units) will be displayed along with analysis graph in full colours.

Technical Specifications:

•    Power supply: 105 - 240Va.c. 50-60Hz 30VADimensions: 330 x 145 x 380 mm
•    Weight: ~ 3kg (approx without stand)
Controller requirements:
•    IBM AT, PS/2 or compatible. 386/486 CPU, 33MHz clock,
•    VGA video, MS-DOS ver 3.3 or higher,
•    one 1.44Mb 3.5" floppy,
•    one 20Mb (minimum) hardisk,
•    serial and parallel interfaces,
•    parallel impact printer (suggested).
Analog-to-Digital Converter
•    Converter type: successive approximation
•    Potential range: ±4,096mV
•    Resolution: ±2mV (12bit)
•    Conversion rate: >=50ksample/sec
Techniques Implemented
•    PSA: Potentiometric Stripping Analysis
•    CCSA: Constant Current Stripping Analysis
•    CPU: Z80 8-bit microprocessor
•    CLOCK: 6.4MHz
•    PROGRAM MEMORY: 32kbytes
•    DATA MEMORY: 32kbytes
•    DIGITAL INTERFACE : Serial RS-232C, fully opto-insulated, 1200 - 38,4OO baud
Current Source
•    Three-electrode system
•    Output voltage compliance: ±12V
•    Response time: >=100 µsec
•    Output impedance: >= 100 Mohm
•    Ranges: ± 100 µA, ± 10µA, ± 1µA, ± 100nA
•    Resolution: 1/4096 of the selected full-scale value
Stand & Cell System
•    MATERIAL: anti-acid, painted polyammide plastic
•    SAMPLE CHANGE: auto -lifting system cell
•    SAMPLE CELL: Pyrex glass (Teflon ?available)
•    OPTIONAL PURGING SYSTEM: two-way automatic gas bubbler
•    STIRRER: computer-controlled propeller-type stirrer
•    ELECTRODES: 6mm glass-body electrodes with standard N6 conical joint
◦    COUNTER Platinum wire
◦    WORKING Glassy Carbon 3mm disk (Gold and Platinum also available)
•    DIMENSIONS: 200 x 160 x 380mm
•    WEIGHT: 2.5kg (approx)
•    Input voltage range: ±10V
•    Input Impedance: >=10 12 ohm
•    Input leakage current: =<10pA
•    Equivalent input noise: =< 25µVpp

Accessories and replacement parts:

Mod. 435/LF - Magnetic Stirrer
Mod. 373/SSG/6J-Z - Ag/AgCl Reference 373 reference electrode
Mod. 805/SPG/6J-Z - Platinum Counter electrode  
Mod. 492

  • 492/GC-3 - Glassy Carbon disk Working electrode (3mm)
  • 492/GO-2 - Gold disk Working electrode (2mm)
  • 492/PT-2 - Platinum Working electrode disk (2mm)

Application Fields:

2435 operatingPSA technique can successfully employed both in industrial and research field. More specifically, analysis on:
Foods and beverages
that means routine testing in wine, juice, milk, where detection of toxic metals like Pb, Cd, Cu or Zn is crucial.
Waters treatment
tap water, fresh water, PSA allows detection of heavy metals without problem of interferences due to the salt presence, enabling analysis without solvent extraction.
Galvanic industries
i.e Pb, Cu and Cu in nickel plating baths
i.e. analysis in raw material used for packaging
windows software supplied with Tracescan is completely open: researcher can built his own analysis simply filling-up set up parameter menu.

Operating principle:

Potentiometric Stripping Analysis (or, more briefly, PSA), still retaining most of the advantages of the electrochemical techniques (low cost, simplicity, fast response), greatly overcomes traditional problems of interference allowing trace analysis directly into the practical sample without need for mineralization or preparation phases (as long as the sample is already in liquid form). While the first accumulation step is identical in all respects to the classical voltammetric technique, the stripping phase is performed uniquely by means of chemical action, i.e.: the active species accumulated into the working electrode are stripped-off by the action of a strong oxidizing solution.
The instrument simply measures the working electrode potential that changes progressively as long as the metals are stripped-away in succession at their different electrochemical potentials.
This Chemical stripping action is quite insensitive to almost any interfering organic matter present in the solution and is also insensitive to the presence of dissolved oxygen in solution (another factor of great interference in the traditional voltammetric analysis).
The constant value time at each metal's redox potential is proportional to the concentration of the metal sample.

Application software:

Model 435 Tracescan is supplied to the final user complete with the application software under WINDOWS®.
Software runs on any PC (486 or Pentium, with WINDOWS 95-98-2k or 3.x). The software allows to obtain full control over all operating parameters of the PSA analysis. Automatic messages are issued as guideline in order to facilitate less skilled operator too. Data collected automatically by the Model 435 are automatically evaluated, compared and graphically displayed along with the final report containing directly the unknown concentration of the elements presents in the sample solution directly in ppm and ppb.

Download Software DEMO for Windows 95 ® (1.600 Kb)

Different methods of the unknown concentration calculation are implemented: single addition, multiple additions, with or without internal standard. Tracescan software also provides several facilities for data files management and final report, by using WINDOWS features. Upon specific request, AMEL can also provide taylored methods for all users facing with specific and repetitive analytical problems, granting the maximum possible automation for not skilled personnel.