Material Guide

Quartz Cuvette UV Cut-Off: 190 nm vs 200 nm vs 220 nm

What the UV cut-off of a quartz cuvette means, how JGS1 / JGS2 / JGS3 differ, and why 190 nm transmission matters for your measurements.

1. What "UV Cut-Off" Means

The UV cut-off is the wavelength below which a material stops transmitting. Below the cut-off, absorbance rises steeply and measurements become unreliable. Quartz cut-offs are quoted at the point where transmittance drops sharply (often ~10% or the conventional 1 mm path reference).

2. Cut-Offs by Grade

Grade	Origin	Typical UV cut-off	Safe measurement range
JGS1 (synthetic)	Synthetic fused silica	~190 nm	190 – 2500 nm
JGS2 (flame-fused)	Natural quartz	~200 – 220 nm	220 – 2500 nm (careful below 220)
JGS3 (IR-grade)	Natural quartz, vacuum-fused	~220 nm (UV)	220 nm – 3500 nm
Optical glass	Borosilicate	~320 nm	Visible only

3. Why 190 nm Matters

Measurements at 200–220 nm (peptide bonds ~210 nm, some pharmaceutical methods) need a cell that transmits below the measurement wavelength — JGS1 only.
Measurements below 200 nm (e.g. 190 nm gas-phase or special methods) require synthetic fused silica.
DNA/protein at 260/280 nm — every quartz grade works; JGS1 is future-proof for all UV work.

4. How to Verify Your Cell’s Cut-Off

Scan an empty cell against air from 190 nm up. A JGS1 cell should stay flat and transmissive down to ~190 nm; a JGS2 cell begins to absorb around 200–220 nm. scuvette includes transmission data on request, and every standard cell is JGS1.

A practical tip: if your routine methods never go below 240 nm, JGS2-class cells are acceptable — but JGS1 costs little more and removes the risk entirely. We stock JGS1 as standard.

Need cells for deep-UV work? Our JGS1 standard line covers 190 nm.
Send us your instrument model and sample type — our engineers will reply within 1 business day with the right specification and a firm price. Contact Scuvette →

Need a hand? Our engineers can help you select the right cuvette for your instrument and application — or supply custom optical cells to your drawing. Contact Scuvette →