Guides for chemical buyers & lab teams
Grades, documentation, regulation, logistics and lab maths — written by chemists for procurement, QC and R&D teams.
HSN Codes for Chemicals: Chapter 28 vs 29 and GST Basics
Correct HSN classification drives duty, GST and export paperwork. Learn how Chapters 28 and 29 differ, when other chapters apply, and GST basics for buyers.
5 min readIndustryWater Treatment Chemicals: Coagulants, Flocculants and PAC
Alum, ferric chloride, PAC and polyacrylamide each clarify water differently. Learn how coagulation and flocculation work and how to choose and dose them.
5 min readLab PracticeStorage and Shelf Life of Laboratory Chemicals
Good storage protects people and keeps reagents within specification. Practical rules for segregation, temperature, moisture, peroxide formers and dating.
4 min readLab PracticeDeuterated Internal Standards in LC-MS Bioanalysis
A good internal standard makes LC-MS quantitation robust. Learn why labelled standards are preferred, how to select one and the pitfalls to avoid.
5 min readLab PracticeHow to Calculate Molarity, Normality and Dilutions
Step-by-step worked examples for preparing solutions: molarity, normality, percent concentrations, diluting concentrated acids and avoiding hydrate errors.
4 min readGuidesShipping Dangerous Goods: UN Numbers, Packing Groups, IMDG
Most laboratory and industrial chemicals are regulated for transport. Learn how classification, UN numbers, packing groups and packaging fit together.
4 min readGuidesIncoterms 2020 for Chemical Exports: EXW, FOB, CIF, DAP
The Incoterm on a chemical quotation decides who pays, who insures and who carries the risk. Here is how the main terms compare, with dangerous goods in mind.
5 min readRegulatoryUS TSCA Import Certification Explained for Importers
Every chemical shipment entering the US needs a TSCA position. Learn positive and negative certification, Inventory status, exemptions and record-keeping.
5 min readRegulatoryImporting Chemicals into the EU: REACH Basics for Buyers
If you import chemicals into the EU, REACH may make you the registrant. Learn the thresholds, roles, exemptions and practical questions to ask suppliers.
5 min readLab PracticeHPLC Solvent Selection Guide: UV Cutoff, Purity and Grades
The mobile phase decides your baseline, pressure and sensitivity. A practical guide to UV cutoffs, viscosity, buffers and choosing the right solvent grade.
4 min readRegulatoryImpurity Reference Standards: Types and Use in ANDA/DMF
Impurity standards are the evidence behind every impurity specification in a generic filing. Learn the types, thresholds and characterisation they require.
4 min readRegulatoryNitrosamine Impurities: Regulatory Limits and Testing
Since 2018, nitrosamines have reshaped impurity control in pharmaceuticals. This overview covers acceptable intakes, NDSRIs, risk assessment and analytical testing.
5 min readGuidesWhat Is a CAS Number and How the Check Digit Works
The CAS number is the most reliable way to specify a chemical. Learn how it is structured, what it does and does not identify, and how to validate one.
4 min readRegulatoryThe 16 Sections of a GHS Safety Data Sheet Explained
Every GHS Safety Data Sheet follows the same 16-section structure. Knowing what sits where helps you find the right information fast when it matters.
4 min readGuidesHow to Read a Certificate of Analysis (COA)
A Certificate of Analysis tells you what was tested on your lot and what the results were. Here is how to read one critically, field by field.
4 min readGuidesAR vs LR vs GR Grade Chemicals: What's the Difference?
Grade names on reagent bottles decide how much you pay and whether your result can be trusted. Here is what AR, LR, GR and related grades actually mean.
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