HPLC Grade chemicals

What HPLC grade means

HPLC grade describes solvents, and some additives, that are purified and tested specifically for use as mobile phases in high-performance liquid chromatography. Ordinary reagent solvents may have acceptable assay but still contain trace UV-absorbing impurities, dissolved stabilisers, particulates or non-volatile residue that show up as baseline drift, ghost peaks and blocked frits. HPLC grade addresses those failure modes directly.

Typical specifications

Values in the table are typical of the grade. The limits that apply to a given product are those stated on its specification and lot Certificate of Analysis.

Where it is used

• Mobile phases for reversed-phase and normal-phase HPLC and UHPLC with UV or PDA detection
• Sample and standard preparation for assay and related-substances methods
• Pharmacopoeial methods that specify chromatography-grade solvents
• Preparative chromatography where fractions are evaporated and residue matters

How it differs from neighbouring grades

AR or ACS grade solvents meet purity and impurity limits but are not necessarily tested for UV transmission or gradient blanks, so they can work for isocratic methods at longer wavelengths but are a risk at low UV. LC-MS grade goes further than HPLC grade by limiting metal ions, which form adducts and suppress ionisation, and by testing for background ions in the mass spectrometer. Spectroscopy grade is optimised for optical transparency in cuvettes rather than chromatographic behaviour. If your method runs at low wavelengths or uses gradients, HPLC or gradient grade is the practical minimum.

Handling tips

Keep bottles tightly closed, since acetonitrile and methanol absorb water and tetrahydrofuran can form peroxides once any stabiliser is depleted. Degas and use promptly after opening, and avoid filtering through membranes that can leach extractables.

Ordering HPLC grade solvents

We supply HPLC and gradient-grade acetonitrile, methanol, water, tetrahydrofuran, isopropanol, n-hexane and other common mobile-phase solvents in glass bottles and larger returnable or single-use containers. Each lot COA reports the UV absorbance values, water content and residue, so you can compare lots before they reach your instrument.