High-flow, dry nitrogen for blow-down concentrators, parallel evaporators, and solvent-reduction workstations. On-site generation delivers 20–70 L/min continuously — enough for the most demanding multi-position evaporator without ever changing a cylinder.
Nitrogen blow-down evaporation directs a gentle stream of dry, inert nitrogen onto the surface of a liquid sample, accelerating solvent evaporation while protecting heat-sensitive analytes from oxidation and thermal degradation.
Individual nitrogen jets directed at each sample vial create a turbulent gas/liquid interface that dramatically accelerates evaporation. Combined with a heated water bath (25–60 °C), this is the fastest gentle concentration method available.
Some evaporators pre-heat the nitrogen gas stream to 40–80 °C before directing it at the sample. Heated gas further accelerates evaporation of high-boiling solvents like DMSO, DMF, and water-based matrices.
Modern parallel evaporators process 12, 24, 48, or 96 samples simultaneously. At 0.5–2 L/min per position, a 48-position unit can consume 24–96 L/min — a volume that depletes nitrogen cylinders within hours.
A standard high-pressure nitrogen cylinder (size T, 6,800 liters) lasts approximately 2–6 hours when feeding a multi-position evaporator. A 48-position blow-down unit running at moderate flow consumes 20–50 L/min — meaning a busy sample prep lab may go through 2–4 cylinders per day.
At $40–80 per cylinder plus rental and delivery fees, the annual gas cost for a single evaporator can reach $15,000–$40,000. Add a second evaporator or increase to 96 positions and the cost doubles.
The operational impact is worse than the cost. Every cylinder swap means stopping evaporation, disconnecting the regulator, rolling a 150-pound cylinder into position, reconnecting, leak testing, and re-pressurizing. If your technician is in the middle of a 48-sample batch and the cylinder runs out, you get incomplete concentration, inconsistent final volumes, and potentially lost samples.
An on-site membrane nitrogen generator delivering 20–70 L/min solves all of these problems permanently. The generator runs continuously, requires no cylinder swaps, and pays for itself in months.
A lab running a 24-position evaporator 6 hours/day at 15 L/min average flow consumes ~5,400 L/day = roughly 1 cylinder/day. At $60/cylinder, that is $15,600/year in gas alone. An NG CASTORE XS iQ 24 pays for itself in under 12 months — and then your nitrogen is essentially free.
Environmental testing: EPA methods 524, 525, 608, 625, and 8270 require solvent concentration of liquid-liquid or solid-phase extracts before GC-MS or LC-MS analysis. Nitrogen blow-down is the standard technique for reducing extract volumes from 50–500 mL to 1–5 mL.
Clinical & toxicology: Blood, urine, and tissue extracts are concentrated under nitrogen before LC-MS/MS analysis for drugs of abuse, therapeutic drug monitoring, and metabolomics panels. Multi-position evaporators process hundreds of patient samples per day.
Food safety: Pesticide residue analysis (QuEChERS), mycotoxin screening, and veterinary drug testing all use nitrogen evaporation to concentrate extracts before chromatographic analysis.
Forensics: Drug seizure analysis, arson investigation extracts, and toxicology specimens require nitrogen blow-down for sample concentration before confirmatory GC-MS or LC-MS analysis.
Pharmaceutical: Metabolite identification, impurity profiling, and stability studies use nitrogen evaporation for sample work-up and concentration before HPLC or mass spectrometry.
Quick reference for nitrogen generator selection by evaporator size and type.
| Evaporator Type | Positions | N₂ Flow Required | Pressure | Recommended Generator |
|---|---|---|---|---|
| Single-position blow-down | 1–6 | 1–6 L/min | 10–20 psi | NG CASTORE XS iQ 15 |
| 12-position evaporator COMMON | 12 | 6–15 L/min | 15–30 psi | NG CASTORE XS iQ 15/24 |
| 24-position evaporator | 24 | 12–30 L/min | 15–30 psi | NG CASTORE XS iQ 36 |
| 48-position evaporator | 48 | 24–50 L/min | 15–30 psi | NG CASTORE XL iQ 50 |
| 96-position microplate | 96 | 20–48 L/min | 10–20 psi | NG CASTORE XL iQ 50 |
| Dual evaporators | 24+24 or 48+12 | 30–60 L/min | 15–30 psi | NG CASTORE XL iQ 70 |
| 3+ evaporators / central supply | Multiple | 50–200+ L/min | 15–60 psi | NG CASTORE PRO / BASIC |
| Evaporator + LC-MS shared | 24 + 1 LC-MS | 30–60 L/min | 15–100 psi | NG CASTORE XL iQ 70 |
Sample evaporation is the single highest-volume nitrogen application in most analytical labs. On-site generation delivers the biggest ROI.
At 2–4 cylinders per day, evaporator labs see payback in 3–9 months. After that, your nitrogen is essentially free. No gas invoices, no rental, no delivery surcharges.
Your 48-sample batch runs to completion every time. No more mid-batch cylinder swaps that cause uneven concentration, variable final volumes, and wasted analyst time.
Constant nitrogen flow and pressure from a generator means every sample in your batch receives identical evaporation conditions. Better reproducibility = better data.
NG CASTORE iQ models include an integrated oil-free compressor. No house air connection needed. Plug into power, connect to your evaporator, and start concentrating.
No more rolling 150-pound cylinders through the lab. No more regulator swaps, leak testing, or high-pressure safety concerns. Just consistent, low-pressure nitrogen on demand.
A single NG CASTORE XL iQ replaces an entire cylinder rack and manifold system. Free up valuable floor space for instruments, not gas storage.
Our nitrogen generators are instrument-agnostic and supply every nitrogen blow-down evaporator on the market.
N-EVAP, MULTIVAP, S-EVAP nitrogen evaporators. 6 to 45 positions. The original nitrogen blow-down evaporator manufacturer.
TurboVap II, TurboVap LV, SPE Dry 96. Automated evaporation with nitrogen gas. 6 to 96 positions for all vial formats.
MiniVap, MicroVap microplate evaporators. 96-well plate nitrogen evaporation for high-throughput sample prep.
FlexiVap nitrogen evaporators. 6 to 34 positions. Heated and unheated models for environmental and clinical labs.
miVac, Rocket Synth centrifugal concentrators with optional nitrogen overlay for oxygen-sensitive samples.
TurboVap, Zymark nitrogen evaporation systems. Legacy and current models. Standard nitrogen gas connections.
N-Vap nitrogen evaporators for EPA method sample concentration. ProVap for high-volume environmental labs.
Central nitrogen supply for labs running 2–6+ evaporators. One NG CASTORE XL iQ or PRO feeds your entire sample prep area.
Tell us which evaporator you use, how many positions it has, and how many hours per day it runs. We will size the right nitrogen generator and calculate your cylinder replacement savings.