VERSATILE ZEEMAN MERCURY ANALYZER RA-915+ WITH NEW PYROLYZER PYRO-915+

METHOD

Atomic absorption spectrometry

PRINCIPLE OF OPERATION

Direct atomic absorption mercury determination (without any pre-treatment procedures) in the samples with complex matrix (foods, vegetation, oil and its products, soils, sediments, various biological materials) is complicated by presence of organic compounds. When such samples are atomized much smoke is produced and practically in all cases the total absorption in the cell is out of the working range of the spectrometer. Using a spectrometer with background correction - Zeeman atomic absorption mercury spectrometer RA-915+ and a developed two-chamber catalyst atomizer (PYRO-915+), the direct mercury determination problem is solved.

After inserting the sample in the first chamber of the atomizer it is heated up to 800 C (all mercury compounds are known to be dissociated at such temperatures). Less volatile mercury compounds are dissociated but more volatile species, e.g. mercury organic compounds, can leave the first chamber as compounds during warming up of the chamber. In addition presented organic compounds of the matrix originate much smoke and variously compounds, which are able to produce strong background absorption in the analytical cell. All products are transported from the first chamber to the second one by the carried gas (in our case it is air). The second chamber is continuously heated about 800 C. There, all mercury compounds are dissociated and smoke and interference compounds are burst producing mostly carbon dioxide and water. Zeeman corrector of the spectrometer eliminates the rest background absorption. The catalyst improves the efficiency of oxidation and dissociation in the second chamber.

• Unique direct mercury determination (no pre-treatment procedures required) in liquid and solid samples (including complex matrix organic samples): waste water, blood, foodstuffs, oil and oil products, bottom sediments, rocks etc. Mercury determination without its preliminary accumulation on a gold trap
• Fast mercury determination without its preliminary accumulation on a gold trap
• Broad dynamic measurement range: 5 orders of magnitude
• Variable temperature of the decomposition chamber allows selection of optimal atomization. Preset modes for various types of samples are embedded in the software
• Heated analytical cell rules out interferences even for a sample with a high content of organic substances and chlorides
• Boost heated function (stepwise heating of the atomizer) allows to control the completeness of the mercury release from the sample
• Monitoring the background absorption during measurement allows effective selection of the permissible weight of samples of any composition, thereby avoiding analysis errors
• Visualization of mercury output from the sample, user-friendly computer interface
• Calibration coefficient is set using standard mercury-containing sample of any composition, high calibration stability
• Automatic control of the air flow rate, no carrier gas is needed 
  

The validity of the method is proved by the agreement between the measured and certified concentrations in various standard complex-matrix samples (see the table below). Note the excellent consistency of the method: the discrepancies between concurrent measurements do not exceed 10% for different sample weights. 
 

All LUMEX equipment is covered by 12-months warranty

Upon request installation and commissioning of LUMEX instruments can be carried out on Customer's site by our service engineers. Consultations and initial training of attendance personnel with due account of Customer's specific needs are performed. Spare parts are delivered and repair is made upon Customer's request (free within the warranty period).