Understanding the Classification of Laboratory Reagents

Laboratory-Reagents

Laboratory Reagents

Most of us working in laboratories use different chemicals but lack required clarity on their grades. Validated Methods specify the grade of reagents to be used. It is important to use specified grades otherwise errors can arise due to contamination from reagents themselves. On the other hand you can incur additional cost in analysis if you use a superior grade of reagent when your analysis does not have such high purity requirements.

Laboratory reagents are classified on the basis of purity and intended use.

Classification based on purity

Technical grade – suitable for non-critical tasks such as rinsing, dissolving, etc

Synthesis grade – for organic synthesis and preparative tasks

Lab grade – covers most solvents used in common laboratory applications

A R grade – used for high precision work. Trace impurities are restricted to lowest possible limits for high precision. Such reagents used mainly for analytical applications, research and quality control . If such reagent meets the ACS specifications it will be denoted as AR (ACS)

ACS grade – ACS stands for American Chemical Society. Such grades are useful for high quality work

General reagent (GR) – reagent that meets or exceed AR grade specifications

Extra pure grade – suitable for laboratory accreditations and also work requiring compliance with pharmacopoeial standard requirements
Classification based on applications

Electronic grade – these have very stringent limits for metallic impurities as required for use in electronic component industry as such as below ppt or ppb levels

HPLC grade – solvents meet strict UV absorbance specifications and are filtered for removal of sub-micron suspended solids. Omnisolv HPLC grade products meeting ACS requirements suitable for use in HPLC applications

Spectroscopy grade – includes solvents of high purity, low residue on boiling and having absorption blank in wavelength region of interest.HPLC/spectroscopy grade for common use in HPLC and spectroscopic applications. Spectroscopy grade salts alkali metal salts having transparency in IR region such as KBr, NaCl, CsI,etc

Acids

Suprapur (E – Merck) – high purity grade acids having metallic impurities in ppb range

Environmental grade (Anachemia) – high purity acids refined through sub- boiling distillation

Environmental grade plus (Anachemia) – produced by additional distillation of environmental grade acids

Pesticide residue analysis applications

HR Omni grade solvents (EMD) – have GC impurities below ppt/ppb levels as tested by ECD detection

Nano grade – meet ACS grade specifications used for extraction and pre-concentration applications

Residue grade solvents – solvents suitable for pesticide residue analysis

Choice of the right grade of reagent is essential for the application in hand and it is also important to use reagents from same source for high precision of results
.
Please do share your comments on the article.

About Dr. Deepak Bhanot

Dr Deepak Bhanot is a seasoned professional having nearly 30 years expertise beginning from sales and product support of analytical instruments. After completing his graduation and post graduation from Delhi University and IIT Delhi he went on to Loughborough University of Technology, UK for doctorate research in analytical chemistry. His mission is to develop training programs on analytical techniques and share his experiences with broad spectrum of users ranging from professionals engaged in analytical development and research as well as young enthusiasts fresh from academics who wish to embark upon a career in analytical industry.

Comments

  1. thank you it was very good & Useful !

Speak Your Mind

*

Get Free and Instant Access to Lifelong Learning!

Lab-Training.Com provides you free ongoing learning on the fundamentals and latest developments in laboratory and analytical sciences. Come be part of our community of 17000 members!

  • Become an expert
  • Tips, Tricks and Troubleshooting
  • Just few minutes a week
  • Latest from the laboratory world
  • Brush up and strengthen your basics
  • Learn new techniques
  • Short and crisp articles