SOPH-1: Marine Sediment Certified Reference Material for the Determination of Butyltin Compounds

The following tables show those constituents for which certified and information values have been established.

The expanded uncertainty (UCRM) in the certified value is equal to U = kuc where uc is the combined standard uncertainty calculated according to the JCGM Guide and k is the coverage factor. It is intended that UCRM accounts for every aspect that reasonably contributes to the uncertainty of the measurement. A coverage factor of 2 was applied for all measurments. The table below lists certified values for SOPH-1 expressed on a dry mass basis.

Table 1: Certified Quantity Values

Compound Mass fraction,
Dibutyltin (as Sn) 174 ± 9
Tributyltin (as Sn) 125 ± 7

Table 2: Information Values

Compound Mass fraction,
Monobutyltin (as Sn) 197

The certified values for SOPH-1 are based on the unweighted mean of results from data submitted by laboratories participating in several recent Comité Consultatif pour la Quantité de Matière (CCQM) comparisons.


CCQM-P18, CCQM-P43 and CCQM-K28 were undertaken in 2002 and 2003 to assess the current capabilities of interested National Metrology Institutes (those which are members of the Consultative Committee for Amount of Substance) and selected outside expert laboratories to quantitate tributyltin and dibutyltin in a prepared marine sediment. These exercises were sanctioned by the CCQM as an activity of the Inorganic Analysis Working Group, and were jointly piloted by the National Research Council Canada (NRC) and LGC Ltd (UK). A detailed report addressing CCQM-P18 is published in Metrologia.

Intended Use

This reference material is primarily intended for use in the calibration of procedures and the development of methods for the determination of (C4H9)3Sn+ (tributyltin, TBT) and (C4H9)2Sn2+ (dibutyltin, DBT) in sediments or materials of a similar matrix. A minimum sample mass of 500 mg is recommended.

Preparation of Material

SOPH-1 was prepared in-house at NRC following gravimetric blending of two NRC CRM marine sediments, PACS-2 and HISS-1, the latter containing negligible concentrations of TBT and thus serving as a solid, inert diluent. Table 3 provide information values about the particle size distribution of SOPH-1.

Table 3: Particle Size of SOPH-1

SOPH Particle size, μm
Median 12.0
Mean 13.8
Mode 18.6

Date of issue: August 2004
Date of expiry: December 2019
Revised: October 2009, December 2011, November 2014, March 2016 (editorial update)

Date modified: