--- title: How to Choose Vials for Light-Sensitive HPLC Samples description: Protect photolabile analytes from preparation to injection. How to choose amber vials, caps and handling methods for light-sensitive HPLC samples. --- [Skip to content](https://blog.chromatographydirect.com/how-to-choose-vials-for-light-sensitive-hplc-samples#main-content) [![cd-logo-header](https://blog.chromatographydirect.com/hs-fs/hubfs/Logos/cd-logo-header.png?width=180&height=68&name=cd-logo-header.png)](https://www.chromatographydirect.com/) - [Products](https://www.chromatographydirect.com/products/vials-and-caps) Show submenu for Products - [Vials & Caps](https://www.chromatographydirect.com/products/vials-and-caps) - [Sample Preparation](https://info.chromatographydirect.com/uct-sample-preparation-products-chromatography-direct) - [Filtration Products](https://www.chromatographydirect.com/products/filtration-products) - [LC Columns & Accessories](https://www.chromatographydirect.com/products/lc-columns-and-accessories) - [Instrument Spares](https://www.chromatographydirect.com/products/instrument-spares) - [Plates & Mats](https://www.chromatographydirect.com/products/plates-and-mats) - [Flash Chromatography](https://www.chromatographydirect.com/products/flash-chromatography) - [Solvent Safety](https://www.chromatographydirect.com/products/solvent-safety) - [GC Columns & Accessories](https://www.chromatographydirect.com/products/gc-columns-and-accessories) - [Dissolution](https://www.chromatographydirect.com/products/dissolution) - [Clinical Kits, Standards and Controls](https://www.chromatographydirect.com/products/clinical-kits-standards-and-controls) - [New Products](https://www.chromatographydirect.com/new-products) - [Knowledge Base](https://www.chromatographydirect.com/knowledge-base) - [About Us](https://www.chromatographydirect.com/about-us) - [Offers](https://www.chromatographydirect.com/offers) - [Blog](https://blog.chromatographydirect.com) Open main navigation Close main navigation - [Products](https://www.chromatographydirect.com/products/vials-and-caps) Show submenu for Products - [Vials & Caps](https://www.chromatographydirect.com/products/vials-and-caps) - [Sample Preparation](https://info.chromatographydirect.com/uct-sample-preparation-products-chromatography-direct) - [Filtration Products](https://www.chromatographydirect.com/products/filtration-products) - [LC Columns & Accessories](https://www.chromatographydirect.com/products/lc-columns-and-accessories) - [Instrument Spares](https://www.chromatographydirect.com/products/instrument-spares) - [Plates & Mats](https://www.chromatographydirect.com/products/plates-and-mats) - [Flash Chromatography](https://www.chromatographydirect.com/products/flash-chromatography) - [Solvent Safety](https://www.chromatographydirect.com/products/solvent-safety) - [GC Columns & Accessories](https://www.chromatographydirect.com/products/gc-columns-and-accessories) - [Dissolution](https://www.chromatographydirect.com/products/dissolution) - [Clinical Kits, Standards and Controls](https://www.chromatographydirect.com/products/clinical-kits-standards-and-controls) - [New Products](https://www.chromatographydirect.com/new-products) - [Knowledge Base](https://www.chromatographydirect.com/knowledge-base) - [About Us](https://www.chromatographydirect.com/about-us) - [Offers](https://www.chromatographydirect.com/offers) - [Blog](https://blog.chromatographydirect.com) - [Contact us](https://info.chromatographydirect.com/contact-chromatography-direct) [Contact us](https://info.chromatographydirect.com/contact-chromatography-direct) --- Oct 12, 2026, 9:00:01 AM # How to Choose Vials for Light-Sensitive HPLC Samples [Chromatography Direct](https://blog.chromatographydirect.com/author/chromatography-direct) Share: [facebook-f icon](http://www.facebook.com/share.php?u=https://blog.chromatographydirect.com/how-to-choose-vials-for-light-sensitive-hplc-samples) [linkedin-in icon](http://www.linkedin.com/shareArticle?mini=true&url=https://blog.chromatographydirect.com/how-to-choose-vials-for-light-sensitive-hplc-samples) [twitter icon](https://twitter.com/intent/tweet?url=https://blog.chromatographydirect.com/how-to-choose-vials-for-light-sensitive-hplc-samples) [envelope icon](mailto:?body=https://blog.chromatographydirect.com/how-to-choose-vials-for-light-sensitive-hplc-samples) Some samples start degrading the moment they're exposed to lab light. If your peak areas drop across a sequence, or unexpected degradant peaks appear in later injections, light could be the cause. The fix starts with the vial. Here's how to choose the right one. ![1596x610-Vials](https://blog.chromatographydirect.com/hs-fs/hubfs/Vials%20and%20Caps/1596x610-Vials.jpg?width=1596&height=610&name=1596x610-Vials.jpg) ## Which samples are light-sensitive? Plenty of common analytes break down under UV and visible light, including: - **Vitamins:** riboflavin (B2), vitamin A, B12, folic acid - **Pharmaceuticals:** nifedipine, tetracyclines, many APIs and impurities flagged in stability studies - **Natural compounds:** carotenoids, chlorophylls, curcumin - **Environmental and food analytes:** some PAHs, aflatoxins and other mycotoxins If you're not sure, check the method, the monograph or the analyte's safety data sheet. When in doubt, run a quick stability test (more on that below). ## Amber glass: the default choice Amber borosilicate vials block most UV and short-wavelength visible light, which is the range that does the damage. For light-sensitive HPLC samples, they should be your starting point. What to look for: - **Type I borosilicate amber glass** for chemical resistance and low leaching - **Consistent wall thickness and colour** so every vial protects to the same level, batch after batch - **The right format for your autosampler:** most instruments take 2 mL, 12 x 32 mm vials with a 9 mm screw or 11 mm crimp/snap closure ## The trade-off with amber Amber glass gets its colour from metal oxides such as iron and titanium. That means slightly higher free ion content than clear 33-expansion glass. For most work this doesn't matter. But if your analytes are **chelating compounds, trace metals, or sensitive to metal adsorption**, consider: - **Silanised (deactivated) amber vials**, which put an inert layer between the glass and your sample - **Clear vials in a light-protected autosampler** (see below) ## Alternatives when amber isn't an option - **Covered or darkened autosampler trays:** many modern autosamplers have opaque doors or covers. Clear vials can work if exposure during prep is minimal. - **Low-volume options** for small sample volumes - **Foil wrapping:** a quick fix, but it can interfere with tray positioning and barcode reading, and it isn't practical at volume. Use it as a stopgap, not a strategy. ## Don't forget the rest of the workflow The vial is only one stage. Light exposure adds up across the whole process: 1. **Prepare samples under low light** or yellow (UV-filtered) lighting where possible. 2. **Fill and cap straight away**, and keep filled vials in a closed box or rack. 3. **Use a cooled autosampler**, because heat and light together speed up degradation. 4. **Keep tray time short:** for long sequences, put the most sensitive samples first or split the run. 5. **Use amber for standards too.** If your calibrants degrade, your quantitation is wrong even when your samples are fine. ## Prove it with a quick stability test Not sure whether your analyte needs protecting? Prepare the same standard in clear and amber vials, leave them in the autosampler, and inject at intervals over your typical run time. If the clear vial's peak area drops or degradant peaks appear, you have your answer and documented evidence for your method file. ## Caps and septa still matter Light protection doesn't replace a good seal. Pair amber vials with the right closure for your application. PTFE/silicone septa suit most HPLC work, and [Ultra Low Bleed Septa](https://www.chromatographydirect.com/products/vials-and-caps/chromatography-vials-and-caps/ultra-low-bleed-septa-products) are the choice for LC-MS. ## The bottom line For light-sensitive HPLC samples, amber Type I borosilicate vials are the safe default. Use silanised amber where metal interaction is a risk, and protect the whole workflow, not just the vial. Want to go deeper on glass types, closures, septa and autosampler compatibility? 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