A practical guide to setting up フロースルーセル, the differences between 2ウェイ, 4ウェイ and funnel-equipped 設計s, and — most importantly — how to pair each セル with the right peristaltic pump tubing for leak-free, bubble-free flow.
A フローキュベット — also called a flow-through セル or flow セル — is a 石英 spectrophotometer セル with open ports on one or more sides so liquid can be pumped continuously through the optical chamber. Instead of filling and emptying a closed セル by hand, the sample flows past the light beam in a closed loop. This makes flow セルs the 標準 detector セル for HPLC, flow-injection analysis (FIA), online / at-line monitoring, and kinetic or time-resolved measurements where you cannot stop to change samples.
Scuvette flow セルs are made from JGS1 optical-グレード 溶融シリカ by optical-contact, 一体成形 (no cement joints in the 光路). They transmit light from 190 nm (far UV) to 2500 nm (near IR), so a single セル covers UV-Vis and most NIR work. The optical chamber has the usual 10 mm × 10 mm 窓s; only the 光路長 and the number/diameter of the side ports change between models.
Our flow セルs share the same optical chamber but differ in port 構成, 光路長 and port (チューブ) diameter. Pick the geometry that matches your instrument and sample 容積:
| Family | Ports | 光路 length | Port Ø (OD) | 容積 |
|---|---|---|---|---|
| Two-Way (Two Ends Open) | 2 | 0.5 – 10 mm | 4 / 5 / 8 / 10 mm | 0.14 – 3.5 mL |
| 4-Port (Four-Port) | 4 | 0.5 – 10 mm | 4 / 5 / 7 mm | 0.14 – 3.5 mL |
| Two-Way with Funnels | 2 + top funnel | 10 mm | 4 mm | 3.5 mL |
| 4-Port with Funnels | 4 + top funnel | 10 mm | 4 mm | 3.5 mL |
Browse the full line-up in フローキュベットs. Short-光路 セルs (0.5–5 mm) are for concentrated samples and fast exchange at low 容積; 10 mm セルs are the general-purpose 標準.
The basic routine is the same for every flow セル — only the number of 接続部 changes:
Different port layouts are used in different ways. Match the セル to the job:
The simplest flow セル: one inlet, one outlet. Use it as a continuous in-line detector (HPLC flow セル, FIA) or for closed-loop circulation. Connect inlet → pump → sample, outlet → waste or back to reservoir. Because there are only two ports, keep the line dead-容積 as small as possible for sharp peaks.
Four ports let you run two inlets and two outlets, which is ideal for:
Funnel-equipped セルs add a top opening above the optical chamber for manual dosing or intermittent feeding without a pump. Pour sample into the funnel; it fills the chamber by gravity and drains out the side ports. Use funnels when:
Short 光路長 means very low internal 容積 (0.14–1.75 mL) and a fast exchange rate — perfect for precious, concentrated or high-value samples and for sharp kinetic traces. Practical notes:
The general-purpose choice (3.5 mL, 10 mm 光路). Tolerant of a wide range of flow rates and the easiest to plumb because the ports are larger (4–10 mm OD). Use them unless you specifically need short-光路 sensitivity or low 容積.
| If you need… | Choose |
|---|---|
| HPLC / FIA in-line detector | Two-Way, 10 mm |
| Post-column reaction / dual feed | 4-Port |
| Batch manual dosing | With Funnels |
| Concentrated sample / fast kinetics | Short-光路 0.5–5 mm |
| General-purpose, tolerant of rate | 10 mm Two-Way / 4-Port |
This is where most leaks and bubbles come from. A peristaltic pump moves liquid by squeezing a flexible チューブ; the チューブ is the only wetted part, so the right チューブ is what makes the connection reliable. Selection has four steps.
The chain is: 石英 port (fixed OD) → barb / luer adapter (optional) → pump tubing → pump head. You have two clean options:
Start from the port OD stamped on the セル (see the table in section 2). Pick a barb whose small step equals that OD, and pump tubing whose ID grips the barb's large step:
| Cell port OD | Barb step (small→large) | Pump チューブ ID (typical) | Typical flow |
|---|---|---|---|
| 4 mm | 4 → 6 mm | 1.6 mm (1/16") | 0.1 – 3 mL/min |
| 5 mm | 5 → 6 mm | 1.6 – 2.4 mm | 0.3 – 8 mL/min |
| 7 mm | 7 → 8 mm | 2.4 – 3.2 mm (3/32"–1/8") | 1 – 25 mL/min |
| 8 mm | 8 → 10 mm | 3.2 mm (1/8") | 2 – 40 mL/min |
| 10 mm | 10 → 12 mm | 3.2 – 4.8 mm | 3 – 80 mL/min |
Rule of thumb: the pump チューブ ID should be 1–2 mm smaller than the barb step it grips so it stretches on and stays put. An ID larger than the barb leaks; an ID far smaller than the port splits the 石英 チューブ end.
Flow rate at a given pump speed is set by チューブ ID (and wall thickness). For the tiny 容積s of short-光路 セルs, use fine-bore tubing (1.6 mm ID) and a low-speed pump head; for 10 mm セルs and fast flushing, 2.4–3.2 mm ID is comfortable. Going above ~4.8 mm ID usually requires an industrial pump head and is rarely needed for a キュベット-scale セル.
Pump heads are built for a specific wall thickness (commonly ~1.6 mm / 0.063" or ~2.4 mm / 0.094"). Use tubing that matches your pump head, or the rollers won't occlude it and you'll get slips, pulsation and back-flow. When in doubt, buy the wall thickness specified by the pump manufacturer.
| 材質 | Best for | Avoid |
|---|---|---|
| Silicone | Aqueous buffers, water, mild solvents; cheapest, very flexible | Strong organics, oils (swells), not for sterile pharma |
| PharMed BPT | Cell culture, biocompatible, low extractables, longer life | Some aggressive organics / hydrocarbons |
| Tygon / PVC blend | General lab, aqueous + many mild organics | Strong acids, chlorinated solvents, ketones |
| Viton (FKM) | Solvents, oils, hydrocarbons, some acids | Ketones, esters, amines |
| Norprene | Long-life general use, wider chemical range than silicone | Very strong organics (test first) |
The 石英 セル itself tolerates almost everything except hydrofluoric acid (HF) and strong alkali (pH > 12). The weak link is the チューブ, so choose the 材質 for your solvent and replace チューブs on a schedule — a worn チューブ leaks and sheds particles.
| Symptom | Likely cause | Fix |
|---|---|---|
| Leak at the port | チューブ ID too large / barb mismatch | Use correct barb + smaller-ID チューブ; add clamp |
| Bubbles in baseline | Line not primed / poor seal pulls air | Re-prime, tighten fittings, lower rate, de-bubble |
| Noisy / pulsing signal | チューブ slips in pump head | Match wall thickness to pump head; replace worn チューブ |
| Rising baseline over time | Residue building in channel | Back-flush, then acid/detergent purge |
| Cross-contamination between runs | Incomplete flush | Longer solvent flush; use separate tubing per reagent |
Q: Can I connect the pump チューブ straight onto the 石英 port?
For 4–6 mm ports at low pressure, yes — stretch fine-bore tubing over the 石英 チューブ. For 7–10 mm ports or any pressure, use a barb/luer adapter; it seals far better and protects the 石英.
Q: Which チューブ size for the 0.5 mm short-光路 セル?
Use 4 mm port → 4→6 mm barb → 1.6 mm ID silicone or PharMed, low pump speed. The tiny chamber needs only a trickle.
Q: My silicone チューブ swells with solvent.
Silicone is not solvent-resistant. Switch to Viton for hydrocarbons/organics or PharMed/Norprene for broader lab use.
Q: How tight should the connection be?
Hand-push the チューブ fully onto the barb until it seats at the step; add a small hose clamp only if you see weeping. Over-clamping cracks the 石英 port.
Q: Do I need different セルs for UV vs NIR?
No — JGS1 溶融シリカ covers 190–2500 nm in one セル. Just keep the 光路長 right for your concentration.
Q: How often should I replace the pump チューブ?
When it looks cloudy, stiff, cracked or starts slipping in the head — typically every few weeks of continuous use, sooner with aggressive solvents.
HPLC、FIA、キネティクスで連続試料流のための入口・出口ポートを持つキュベットです。ねじ蓋キュベット。
通常は単光束用に2ポート（入／出）、多重または基準光路用に3–4ポート（例：3-Portまたは4-Port light）です。フローキュベットの例。
一般的に10 mm。フローセルは標準光学光路を維持します。光路長ガイド。
はい — UVフロー測定用の石英で、PTFEまたは他の不活性継手を使用します。石英 vs ガラス。
正しく組み付けられたフローセルは通常圧力で液漏れしません。互換チューブ（例：8 mmチューブ）を使用してください。チューブキュベット。
各ラン間に溶媒ですすぎ、継手を分解して十分に洗浄してください。洗浄プロトコル。