The Laboratory of Rare Earth Elements Geochemistry and Ecogeochemistry

The United Institute of Geology, Geophysics and Mineralogy Russian Academy of Science University Ave. 3, Novosibirsk 630090, Russia E-mail: [email protected] Phone: (7-3832) 35-46-59

The Laboratory belongs to the Analytical Center of the United Institute of Geology, Geophysics and Mineralogy. Utilizing the sophisticated instrumentation of the Analytical Center, LEGRE participates in a number of independent scientific and applied projects focusing primarily on environmental impacts of industrial and nuclear pollution. The geographic scope of the projects in which the Laboratory participated over the last years includes Southern, Southeastern and Central Siberia, Altay and Kazakhstan. Certified by the Bureau of Standards of the Russian Federation, LEGRE performs sampling, analyses and evaluations of environmental conditions for State and local Governments and is qualified to make conclusions and recommendations pertaining to human health and health policies.

LEGRE consists of three related analytical and scientific teams: neutron activation analysis group, instrumental and radiochemical analysis group and gamma spectrometry group.

The neutron activation analyses are being conducted using high-resolution semiconductor gamma-spectrometry. The instruments used in LEGRE include three newest 1996 multichannel analyzers IN-96 by Intertechniques and gamma-spectrometer by Eurisys Mesures (France), two large-volume Germanium detectors, one planar X-ray range detector and an ultrapure Germanium detector. This equipment is used primarily for full elemental analyses of solid substances, including, but not limited to, rock, soil and sediment samples, minerals, ores and building materials.

In addition the new methods are being developed to approach the analyses of other objects. So far the standard spectrum of measured elements includes Sr, Cr, Fe, Co, As, Sb, Cs, Ba, La, Ce, Nd, Eu, Gd, Tb, Yb, Lu, Hf, Ta, Tl and U. Typical detection limits are 1 to 0.01 ppm. Custom methods are being developed that allow significant decrease of these detection limits. Precision of measurements varies from 5 to 15%. The existing equipment also is used to study surface elemental distribution and volume (3D) distribution of elements in particulate materials.

The group completed the analyses of objects as unique as the samples from super-deep ocean drilling, lunar rocks, etc, and demonstrated high degree of conformity of measurements with the number of internationally recognized analytical laboratories. Analytical capacity of the group is 700 samples / year.

Instrumental and radiochemical analysis group uses the following instrumentation:

1984 Nokia LP 4900B multichannel analyzer (Finland).
Detector DGDK-VOV-3 (1995, Russia).
Detector DGDK-100V (1996, Russia).
X-ray detector EG-PX (1996).

Besides standard instrumental analyses the group also conducts measurements of rare earths in the ultrabasic rocks using the method of radiochemical separation and enrichment thus achieving up to 2 orders of magnitude decrease in detection limits compared to standard methods. The group has large experience measuring Rb, Sr, It, Zr, Nb in 10-30 mg solid rock and mineral samples with the detection limit of 0.1 ppm. Analytical capacity of the group for this method is 20 and up samples per day. Bulk gamma-spectrometric analyses are providing detection down to 3*10^-7 (0.3 ppm) for U (Ra) and Th, and 0.03% for K⁴⁰ (using large samples). Analytical capacity for this type of measurements is 5000 samples / year.

Starting in 1996 the group uses an Eurisys Mesures alpha-beta spectrometer that allows measurements of alpha and beta emitting radionuclides.

Gamma spectrometry group is equipped with two multichannel analyzers AMA-02, AMA-03 and a 200 x 200 mm scintillation NaI(Tl) crystal. This equipment is specifically designed for very low level gamma-spectrometry and are installed and operated in the specially constructed for this purpose Chamber of the Low Natural Radioactive Background (KANIFER). KANIFER is a unique facility built almost 40 feet underground with thick concrete walls which allow to suppress any irregular radioactive emisions existing on the surface. The instrument chamber inside KANIFER is made of foot-thick lead blocks to almost completely eliminate even the very small natural radiation (12-14 mkR/h at the location of the facility). KANIFER has been designed and built with the assistance of the National Institute of Atomic Energy of Russia and allows measurements of very low concentrations of radioactive isotopes:

Isotope	Standard detection limit	Custom detection limit
K⁴⁰	2*10^-5 (20 ppm)	Not attempted
Th	10^-7 (0.1 ppm)	Not attempted
U-series	5*10^-8 (0.05 ppm)	Not attempted
Cs¹³⁷	10^-15 Ku/g	10^-16 Ku/g and lower

Analytical capacity of KANIFER is 2-3 samples per day.

After an extensive cross-calibration work with domestic and international analytical standards, the large experience and achievements of the Analytical Center and Laboratory 775 have been recognized by the State. On April, 10, 1996 the National Bureau of Standards of the Russian Federation (Gosstandart) issued the Accreditation Certificate No. RU. 0001510590 confirming that the Analytical Center / Laboratory 775 is a laboratory federally certified to complete highest quality environmental analyses.

Last updated on April 16, 2002.

Address your comments and questions to Pavel Romashkin.