5735 GW, Aarle-Rixtel  - The Netherlands  | +31492745710 | sales@mswil.com

VICI 360 Connectors

Making meaningful connections

Often our customers ask us: “How do I make my connections work in my nLC-MS set-up” or a variant of this phrase. Therefore, we will provide our insight into this misty territory, with many options and pitfalls on this page.

The first question for you to answer is: “What do I want to connect and with what purpose”. Is it “just” a coupling between a transfer line and a column or emitter, or do you want to turn the connection into a Liquid Junction at the same time. In latter case, you may wish to look into some electrical safety features at the same time.

Frequently made nLC connections

Some connections are made more than others, most nLC connections are straight through and some make use of a t-piece or cross. T’s and Crosses are used to make Liquid Junctions , using gold or platinum electrodes/wires, but T’s may also be used to facilitate vented trap-LC set-up’s. At the end of the day the fittings used are of limited specification, but whatever you combine, things do have to fit!

Here are some examples you may find being used:

VICI nLC Connections
VICI nLC Connections 2

Frequently used and Novel connectors

Over the years a lot has stayed the same in nanoLC-land, mainly due to the resistance to change in the realms of the larger vendors. Connections offered today have been stable over a 10 year plus period. Even though they say “never to change a winning team”, developments do not stop and often may improve the finicky way nanoLC connections are made. In making tight connections it’s all about dimensions.

1) Dimensions

Let’s start with some well used Outer Diameter (OD) dimensions:

Peek/Peeksil tubing:

Fused Silica tubing:


1/16″ of 1/32″

360-365µm (widely used) or 280µm (UltiMate™ 3000 RSLCnano System)

150µm or 360µm

2) Nuts and bolds

Secondly there are a number of different connectors that ensure a zero dead volume connection. Some examples are:

Viper™ Fingertight Fittings1/16” 10-32Pre-connected to tubing/column
NanoConnect Fingertight Fittings1/16” 10-32Pre-connected to tubing/column
VICI 360 Nuts for 360µm FS tubingProprietarySelf-Assembly
IDEX MicroTight for 360µm FS tubingProprietarySelf-Assembly
VALCO Steel Nut and Ferrule1/16” – 1/32”Self or Pre-assembled
Zircofit 1/16” 10-32Make your own fixed connection

nanoViper™ Fingertight; Thermo Scientific™

Valco 1/16” Stainless Steel Nut& Ferrule

Valco 1/32” Stainless Steel Nut& Ferrule

ZircoFit™ UHPLC Fittings; Prolab

IDEX MicroTight® Fitting

NanoConnect Fitting – PEEK

VICI 360µm FS Connector – PEEK

VICI 360µm FS Connector – STEEL

NanoConnect Fitting – PEEK

As you can see there is a wide range of products available to make connections work, however some work better that others. 10 years ago one had no choice but to use sleeves, today there are a number of options that will allow for easy leak tight connections on 360µm OD Fused Silica lines.

3) Unions

The unions and crosses themselves also come in different variants:

TypeBrandPart NoMaterialDescription
ZDV UnionVICIC360UFS2Steel360µm FS lines direct with 360 nut
IDEXP771Polymer360µm FS lines with sleeve 1/32″ nut
TeeVICIC360TS62Steel360µm connections; 50µm bore
IDEXMicroTee P-88Peek360µm connections; 150µm bore
IDEXVHP MicroTee UH-750Steel360µm connections; 250µm bore
CrossVICIC360XS62Steel360µm connections; 50µm bore
IDEXMicroCrossPeek360µm connections; 150µm bore
IDEXVHP MicroCrossSteel360µm connections; 250µm bore



IDEX MicroTee



IDEX MicroCross PEEK



Unions are made to ensure a “Zero Dead Volume” connection. One note here, to clarify, “zero dead volume” does not mean that there is no volume between the two ends you are connecting. It means that there is no void volume between the ends, many ZDV-connectors have a bore in the metal divider between the lines, if the hole in the divider is similar to the inner diameter of the tubing you are connecting, then the volume in the divider is not considered “dead volume”.

The rational is that as the inner diameter of the continuous line (tube 1 – union – tube 2) is not expanded, and therefore doesn’t affect the flow, the hole is counted as part of the flow line. Dead volume, that causes your chromatography peaks to broaden, is a larger volume in which the laminar flow is disturbed. An extreme example of this is the UV-detector cells that used to be placed in-line with a Mass Spectrometer. Having said that also poorly made fittings cause dead volume and they are the main cause for dead volume in a nanoLC system, so be careful when making your own.

Click here to view all VICI products in our online catalog, and to request your quote.

Liquid Junction Mount

MS Wil developed a solution to mount your VICI union to your Thermo Nanospray Flex Ion Source multipurpose adapter. This includes the following four liquid junction mounts:

MSWil LJ 1 DetailMSWil LJ Detail
Liquid Junction mount to place VICI C360UFS2 union in the Thermo Nanospray Flex Ion Source multipurpose adapter.Liquid Junction mount to place VICI C360RU.5FS2 union in the Thermo Nanospray Flex Ion Source multipurpose adapter.
MSWil LJ DetailMSW-LJ-4
Liquid Junction mount to place VICI C360RU1FS6 union in the Thermo Nanospray Flex Ion Source multipurpose adapter.Liquid Junction mount to place the VICI union fitted on CoAnn columns in the Thermo Nanospray Flex Ion Source multipurpose adapter.

Request your quote for one of our liquid junction mounts in our online catalog.

For more information on VICI, click here.

Related Articles: