Chemistry lab

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The chemical processing for inorganic analyses are carried out in this section. The target sample (ex. silicate rocks, minerals, water samples and organic materials, etc.) are processed by sequence in each room; sample weighing, digestion by an acid treatment, separation and/or purification of target elements, etc. By the equipment of an all fresh air system, clean air passed through the HEPA filter is always introduced in each room. The cleanness of the rooms is class of ~1000, and, 10 in the clean benches. Deionized water (Milli-Q) are supplied in each room from the water production equipment (Milli-Q system) installed in the cleanroom corridor. Further, reagents preparation and sample container-washing are also performed in this section.

Chemistry lab includes: Washing room, Reagents room, Boron chemistry room, Weighing room, and Ultimate clean room.

Washing room

The container before or after of chemical analysis are washed in this room. Two pair of Milli-Q water tap supply and sink are available. Clean evaporator which has same system as in the ultimate clean room are installed, and the container is washed by heated in a clean environment. As use for repeating, washing procedure of Teflon containers take 7 steps, corresponds to 7 days.

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Reagents room

Analytical reagents are stored in this room. The water and acids are distilled using 2- bottle distillation system installed in clean bench. Also dilution and titration of the reagents are performed in this room.

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Boron chemistry room

Boron chemistry system: This system is especially for Boron concentration and isotope analysis. In order to prevent the blank contamination from the environment and also to prevent isotopic fractionation during sample preparation such as acid decomposition and drying etc., sample operation is performed in this low blank glovebox and evaporators. There are also four clean bench in this room

Loading Bench: The sample after the elemental separation and purification are load onto a "filament" at this clean bench for the isotope analysis by TIMS.

Methods and techniques:

Sample preparation for B isotope analysis:
• Nakamura et al. (1992). Precise boron isotopic analysis of natural rock samples using a boron mannitol complex, Chemical Geology: Isotope Geoscience section, 94(3), 193-204.
• T. Ishikawa and E. Nakamura (1993). Boron isotope systematics of marine-sediments, Earth and Planetary Science Letters, 117(3-4), 567-580.

Sample preparation for B, HFSE, Ti, Mo, Sn and Sb concentration determination:
• Tanaka et al. (2003). Suppression of Zr, Nb, Hf and Ta coprecipitation in fluoride compounds for determination in Ca-rich materials, Journal of Analytical Atomic Spectrometry, 18(12), 1458-1463.

Boron Chemistry - Spherical Image - RICOH THETA

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Weighing room

Three of balances are available. Weighing from 1 x 10² g to 1 x 10^-6 g is accurately performed. In general concentration analysis, several tens of mg sample are weighed, and the error at this time is less than 1%.

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Ultimate clean room

Nine of clean benches (class of 10), two of clean evaporator systems (4 branches in each), ultra-sonication devices, closed-small-evaporation-systems named “MUKADE” are installed. Sample decomposition procedure such as acid addition, heating and drying, etc. are proceeded effectively by these systems and in ultra-clean environment. Ion chromatographic operations (separation and purification of the target element using an ion exchange resin) are also processed in this room. It is available of the sample preparation for more than 54 element concentration analysis, more than 7 isotope analyses.

Methods and techniques:

Zhou et al. (2019) A Method to Suppress Isobaric and Polyatomic Interferences for Measurements of Highly Siderophile Elements in Desilicified Geological Samples, Geostandards and Geoanalytical Research, 43(4), 611-633.

Makishima et al. (2009) Precise Elemental and Isotopic Analyses in Silicate Samples Employing ICP-MS: Application of Hydrofluoric Acid Solution and Analytical Techniques, Analytical Sciences, 25(10), 1181-1187.

A. Makishima and E. Nakamura (2008) New preconcentration technique of Zr, Nb, Mo, Hf, Ta and W employing coprecipitation with Ti compounds: Its application to Lu-Hf system and sequential Pb-Sr-Nd-Sm separation, Geochemical Journal, 42(2), 199-206 (2008).

Makishima et al. (2008) New sequential separation procedure for Sr, Nd and Pb isotope ratio measurement in geological material using MC-ICP-MS and TIMS, Geochemical Journal, 42(3), 237-246 (2008).

Lu et al. (2007) Coprecipitation of Ti, Mo, Sn and Sb with fluorides and application to determination of B, Ti, Zr, Nb, Mo, Sn, Sb, Hf and Ta by ICP-MS, Chemical Geology, 236(1-2), 13-26.

Lu et al. (2007) Purification of Hf in silicate materials using extraction chromatographic resin, and its application to precise determination of ¹⁷⁶Hf/¹⁷⁷Hf by MC-ICP-MS with ¹⁷⁹Hf spike, Journal of Analytical Atomic Spectrometry, 22, 69-76.

A. Makishima and E. Nakamura (2006) Determination of major, minor and trace elements in silicate samples by ICP-QMS and ICP-SFMS applying isotope dilution-internal standardisation (ID-IS) and multi-stage internal standardisation, Geostandards and Geoanalytical Research, 30(3), 245-271 (2006).

Nakamura et al. (2003) Comprehensive geochemical analyses of small amounts (< 100mg) of extraterrestrial samples for the analytical competition related to the sample return mission MUSES-C, The Institute of Space and Astronautical Science Report SP, 16, 49-101.

Makishima et al. (2002) Separation of titanium from silicates for isotopic ratio determination using multiple collector ICP-MS, Journal of Analytical and Atomic Spectrometry, 17(10), 1290-1294.

Makishima et al. (2001) A group separation method of ruthenium, palladium, rhenium, osmium, iridium and platinum using their bromo complexes and an anion exchange resin, Analytical Chemistry, 73(21), 5240-5246.

Yokoyama et al. (1999) Evaluation of the coprecipitation of incompatible trace elements with fluoride during silicate rock dissolution by acid digestion, Chemical Geology, 157(3-4), 175-187.

Yokoyama et al. (1999) Separation of thorium and uranium from silicate rock samplesusing two commercial extraction chromatographic resins, Analytical Chemistry, 71(1), 135-141.

Ultimate Clean Room - Spherical Image - RICOH THETA