For laboratories evaluating GC-MS sample concentrators, Organomation’s MULTIVAP combines parallel nitrogen blowdown with controlled heating, adjustable gas flow, and row-by-row shutoff in configurations accommodating up to 100 samples. It is designed to concentrate liquid extracts—a different task from capturing volatile analytes with purge-and-trap concentrators.
The practical advantage is control over a batch: matched sample holders, a shared gas manifold, and timed operation help laboratories standardize the concentration step rather than manage each extract separately.
In gas chromatography mass spectrometry, sample concentration can reduce an extract’s solvent volume before injection or support a method-defined solvent exchange. MULTIVAP directs nitrogen through needles or glass pipettes onto the liquid surface while a water bath or dry block supplies controlled heat.
For environmental laboratories, EPA Method 3510C provides a specific example: it describes nitrogen blowdown as an option for final extract concentration and includes preparation conditions for analysis by Method 8270. EPA Method 8270E addresses semivolatile organic compounds in prepared extracts. These methods establish the application context; they do not establish that every MULTIVAP configuration or operating condition is validated for every analyte.
Pesticide laboratories may also incorporate nitrogen evaporation into validated extract-preparation workflows, but evaporation is not automatically beneficial for every target compound. European Union Reference Laboratory work identifies volatile pesticides, including dichlorvos, as vulnerable to losses during solvent evaporation.
MULTIVAP configurations include 9, 30, 48, and 80 positions with dry-block heating, plus 64- and 100-position water-bath models. For high-volume GC-MS laboratories, vessel dimensions and heating requirements help narrow the choice.
| Configuration | Heating platform | Vessel outside diameter | Gas shutoff grouping |
|---|---|---|---|
| 48-position MULTIVAP | Dry block, 30–120°C | 10–22 mm | Rows of 6 |
| 80-position MULTIVAP | Dry block, 30–120°C | 10–17 mm | Rows of 8 |
| 100-position MULTIVAP | Water bath, 30–100°C | 11–22 mm | Rows of 10 |
These are instrument heating ranges, not recommended operating temperatures for all GC-MS extracts. The analytical method and analyte stability—not the heater’s maximum setting—should govern evaporation conditions.
The dry-block models use customized blocks or inserts fitted to the laboratory’s vessels, while the 100-position water-bath model uses a customized sample rack. Confirm both vessel diameter and length before selecting a configuration.
Uniform evaporation starts with comparable conditions across the batch. MULTIVAP’s fitted dry-block inserts promote even heat transfer, while its water-bath configuration provides a common heating medium around the vessels.
The adjustable manifold also allows the analyst to establish needle height across the sample array. Together, these features support consistent processing of similar extracts, but they do not eliminate differences caused by starting volume, solvent composition, or operating conditions.
For timed concentration to a residual volume, Organomation’s manuals specify matching tube size, starting volume, gas flow, and heating setpoint, with a trial run to establish the required duration. Standardizing those variables is essential before transferring a procedure into routine laboratory sample preparation.
MULTIVAP provides three complementary process controls:
Timed shutoff is not liquid-level detection. A timer stops the selected services after elapsed time; achieving a particular final volume requires an established procedure and endpoint verification.
MULTIVAP offers a substantially lower published nitrogen supply-flow requirement than the 48-position TurboVap LV configuration—a relevant distinction when evaluating laboratory gas infrastructure.
| System | Sample positions | Published supply-flow figure |
|---|---|---|
| MULTIVAP dry block | 48 | 16 L/min in Organomation’s generator-sizing chart |
| MULTIVAP water bath | 100 | 33 L/min in Organomation’s generator-sizing chart |
| TurboVap LV | 48 | 160 L/min for Classic-equivalent capability; 200 L/min for full capability |
These are published supply-sizing figures, not a head-to-head measurement of nitrogen consumed per completed sample. Total consumption depends on operating flow, active positions, and evaporation time, so a defensible comparison should use the same solvent load, endpoint, and recovery requirements.
MULTIVAP also addresses avoidable gas use during everyday operation: unused rows can be shut off, and timed control can prevent nitrogen from continuing indefinitely after the selected run interval. TurboVap LV also provides independent row control, so row shutoff should not be presented as exclusive to MULTIVAP.
For a purchasing evaluation, ask two questions: can the gas supply support the required flow, and how much nitrogen does the validated procedure consume per acceptable result?
The objective is not simply to remove solvent quickly; it is to reach the required final volume while retaining the compounds being measured. EPA Method 3510C cautions against drying extracts under its normal procedure and warns that semivolatile analytes may be lost below 1 mL.
European Commission pesticide guidance similarly recommends minimizing evaporation temperature and avoiding vigorous boiling or droplet dispersion. A keeper solvent may help in an appropriate method, but published GC-MS research shows that keeper selection can affect both recovery and chromatographic behavior.
A practical method-transfer checklist includes:
Operate the instrument in an appropriately ventilated chemical fume hood and follow the model-specific manual’s solvent and safety restrictions.
GC-MS sample concentrators are not all interchangeable. MULTIVAP concentrates a liquid extract by removing solvent; purge-and-trap concentrators deliberately transfer volatile analytes into a gas stream, capture them on a sorbent, and subsequently desorb them into the GC.
| Workflow question | MULTIVAP nitrogen blowdown | Purge-and-trap concentration |
|---|---|---|
| What is collected for analysis? | The concentrated liquid extract | Volatile analytes captured from the purge stream |
| Where must target analytes remain? | In the residual liquid during solvent removal | On the trap until desorption |
| Relevant method context | Final concentration of suitable solvent extracts, such as those prepared under Method 3510C | VOC preparation under Method 5030C for GC-MS Method 8260 |
For volatile compound analysis, this distinction is critical: an analyte escaping during open nitrogen blowdown is not being captured for measurement. MULTIVAP should therefore be positioned for suitable, validated solvent-extract workflows—not as a substitute for purge-and-trap VOC analysis.
The MULTIVAP family accommodates up to 100 samples per batch, with the appropriate model determined by vessel dimensions and heating requirements.
MULTIVAP supports timed shutoff, but the documented controls do not measure a 1 mL liquid endpoint; a timed residual-volume procedure requires experimental setup and verification.
MULTIVAP has lower published supply-flow requirements than the cited TurboVap LV configuration, and it can limit unnecessary flow through unused rows or beyond a programmed interval. Actual nitrogen savings per sample require a matched workflow comparison.
Explore the MULTIVAP range, then share your target analytes, solvent, starting and final volumes, batch size, vessel dimensions, and nitrogen source with Organomation. Use those details to identify a configuration and plan an application-specific evaluation.