Proof of Trust and Reliability

Good Delivery Referee

TANAKA is working to create a global standard for precious metals.


TANAKA is the only accredited Good Delivery Referee in Japan that assesses accredited precious metal refiners to ensure the quality of globally-marketed precious metals.

TANAKA appointed Good Delivery Referee, demonstrating the world-class standard of its technologies

In December 2003, TANAKA was accredited as Good Delivery Referee for gold and silver by The London Bullion Market Association (LBMA), the most prestigious trade organization of the global gold and silver market.

In order to offer high-quality precious metal materials and assembling parts in the electrical and electronic industries, TANAKA has been developing high-standard metal processing technologies that produce high-purity metals (gold: 999.9) for many years. In addition, TANAKA is approved with its highly skilled ability to produce accurate alloy reference samples to assess accredited refiners. With its assay precision, TANAKA can also inspect and evaluate samples manufactured by refiners.

There are only five Good Delivery Referees in the world, and their roles are to (1) assess the gold and silver melting technologies and analytical skills of all accredited gold and silver refiners and (2) accredit new refiners.

TANAKA’s appointment as a Good Delivery Referee is signifying the global recognition that its melting technologies and analytical skills receive.

TANAKA’s appointment as a Good Deliver Referee proves that:

  • TANAKA possesses the world-class technologies required to assess producers around the world;
  • TANAKA takes the responsibility of ensuring the quality of gold and silver throughout the world; and
  • TANAKA can be relied upon, particularly given that it is one of only five Good Deliver Referees in the world and the only one in Japan.

Production of analytical gold and silver reference samples for solid emission spectrometry

For a project established by the world’s leading precious metal-related companies and led by the LBMA, TANAKA was commissioned to produce the industry’s first globally recognized reference sample for gold analysis. TANAKA was able to produce the sample successfully thanks to its proprietary technologies for the production of homogeneous alloys and the precision alloying of various elements. Based on this performance, TANAKA was also commissioned and successfully produces silver reference samples. The LBMA has been selling the gold reference samples throughout the world since 2009, and the silver samples since 2020.

TANAKA plays a central role as an LPPM-approved Good Delivery Referee.

In April 2009, TANAKA was appointed as a Good Delivery Referee for London Platinum & Palladium Market (LPPM). Since then, TANAKA has continued to polish our melting technologies and analytical skills. There are only six LPPM Good Delivery Referees in the world at present, and TANAKA is the only one in Japan.

The LPPM, which was established in May 1987 after experiencing precursor’s long history, is the only globally recognized organization in the world that accredits refiners in order to ensure that platinum and palladium transactions are conducted fairly.

In June 2009, the LPPM posted its Good Delivery Rules on its website and launched a re-accreditation system (referred to as “Proactive Monitoring (PAM)”, to follow the same system as LBMA which had been introduced for gold and silver in 2004) for platinum and palladium. As a Good Delivery Referee, TANAKA’s mission is growing in scale.

Platinum and palladium are used as important materials in an even wider range of industrial fields than gold and silver. These fields include the automotive, electrical, and electronic industries, as well as the asset trading markets. Needless to say, given its high-level analytical skills and its advanced technologies and abundant experience in the field of industrial precious metal processing, TANAKA is expected to play an increasingly prominent role in the LPPM.

With its involvement in the LPPM and the core specialties built up over the years, TANAKA remains committed to making a significant contribution to the world.

We undertake contract manufacturing of standardization samples for optical emission spectrometry. Please contact us for further details.

Our Analytical Techniques Support Customer Confidence in TANAKA

We meet customer expectations through the various instruments, techniques, and high-level skills we employ.

As a company dealing with precious metals, we believe that assay values form the foundation of the confidence that our customers and society as a whole have in us. Given this, we continue to strive to improve analytical accuracy and develop new technologies.


Classification of Analysis based on Purpose and Analytical Methods



Towards International Standards

Accredited to ISO/IEC17025

ISO/IEC 17025 is the international standard that defines the general requirements for competence in examination or calibration. TANAKA has obtained ISO/IEC17025 accreditation for its analytical techniques with platinum, gold, silver and palladium, the precious metals it deals with most.

The accreditation encompasses the analysis of metals in gold bullion (36 elements), platinum (40 elements), palladium (40 elements), and silver (37 elements) using an ICP-OES based on JIS H 6310, JIS H 6312, JIS H 6313,ISO 15096, and JIS K 0116 standards.

Our ISO/IEC 17025 certificate