There are several different names in China and other countries for Reference Materials and also different names with different systems. Here we use Reference Materials (RM). There are 2 measuring standard substances in ISO system which are Reference Materials (RM) and Certified Reference Materials (CRM).

According to ISO Guide 30, Reference Materials/Standard Materials are uniform and stable substances with one or more than one specific properties, and they are also materials or substances which are used to measure the process, evaluate measuring ways or assign materials. The certified reference material has one advantage which is it can figure 1 or more than one specifics by measurable effective procedure, and with relating to the same certificate, it provides the value of the specified property, related uncertainty and measuring traceable statement. The similarities and differences between CRM and RM are below the sheet:


RM is produced based on ISO 17034:2016 (Standard Materials/Standard Samples Producer Competency Recognition Criteria), so what is ISO 17034?

  • ISO 17034 is a standard materials/standard samples producer competency recognition international standard.
  • Implement quality supervision from raw materials selecting, producing, quality supervision, transportation and storage.
  • Producing: raw materials selecting and purifying, production planning and controlling,
  • Description: detecting way, uncertainty and traceability.
  • Batch stability evaluating.
  • ISO Guide 34 was changed into ISO 17034 from Nov. 2016.

According to purity, reagent specifications have 7 purities includes HighPure, spectrum purity, benchmark, spectral purity, guaranteed purity, analytical purity and chemical purity. Guaranteed reagent, analytical reagent and chemical reagent are 3 main quality indexes promulgated by national and competent department.

  1. Guaranteed reagent (GR), also named as the first-class or guaranteed reagent with 99.8%. It has the highest purity and lowest impurity, used in important precise analysis and scientific research with the green label.
  2. Analytical Reagent (AR), also named the second-class reagent, ≥99.7%. Ater AR, it’s used in important analysis and general research with red label.
  3. Chemical purity (CP), also named the third-class reagent, it has big difference to AR, used in industrial and mining and the school general analysis, with blue (deep blue) label.
  4. Laboratory reagent (LR), also named the fourth-class reagent.

The reagent which is higher than guaranteed is HighPure reagent (≥99.9%). The HighPure reagent is developed from the genera reagent, and it’s used for special research and produced by special way. Its impurity is less than the guaranteed on more than 2 magnitudes. Therefore the HighPure reagent especially fits for trace analysis and the guaranteed reagent can’t do it. Except for making national standard for few products (like HighPure boric acid, HighPure Glacial Acetic Acid, HighPure Hydrofluoric Acid), the most HighPure reagents’ quality standards are not uniform, so given different names like HighPure, ExtraPure, UltraPure, Spectral Pure.

The HighPure reagent is generally applied on Chromatographic pure reagent and Spectral pure reagent. Furthermore, circuit and liquid crystal industrials have their own standard HighPure reagent. But the HighPure reagent isn’t generally used on the area with analysis reagent, like standard solution preparation, titrant and etc., but except for HighPure simple substance. That’s to say the HighPure reagent is not a measuring concept material, but Reference Materials belong to the measuring concept. The HighPure reagent’s production is guided by ISO9001. Different industrials have different the HighPure reagent marking ways, the general marking is suing the number 9. For example, if the purity is 99.999%, we got five numbers 9 so we use 5N; if the purity is 99.995%, we got four numbers 9 and one number 5, so we use 4.5N

The HighPure reagent doesn’t need uncertainty and traceable, because the purity and impurity controlling have no requirements for Metrology, so Reference Materials production need high precise requirement.

Welch Materials A2S already passed  ISO9001 and ISO guide 34 (now ISO17034), presently we can provide high quality pure Reference Materials, single standard solution and mix standards solution. We can also customize for customers, like GB2763, GB23200 series.

If you have any problem or require further information, please contact info@welchmat

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