Hardware manual

6-4 Agilent 7500 Series ICP-MS Hardware Manual

6 Technical Information

sample uptake rate to vary, when sample viscosity and sample head volume

above the level of the sample aspiration tube change and it can only be used

when the sample matrix is similar to that of the standard solution.

Nebulizer

There are five types of nebulizers available:

1 Babington nebulizer (BN)

2 Concentric nebulizer (CN)

3 Micro flow nebulizer

4 PFA Concentric Nebulizer

5 Crossflow nebulizer (CF)

The carrier gas is supplied to the nebulizer and the make- up gas is supplied to

the spray chamber end cap. The typical total gas flow rate of the carrier gas

and the make- up gas is 1.2±0.1 L/min for normal plasma conditions. The

carrier gas pressure depends on the nebulizer. The optimal flow rate depends

on the diameter of the torch injector; φ2.5 mm is used as the standard torch,

but if φ1.5 mm is used, the optimal flow rate is about 0.85 L/min. The make- up

gas, in general, is not required; it will normally only be added to the spray

chamber when the cool plasma conditions are used or the carrier gas pressure

is not high enough.

The Ar gas supply pressure is set to 700kPa. The tubing used for the carrier

and make- up gas lines is φ4.0 mm (0.5 mm thickness) PFA.

Tubing inserts must be used for connecting the tubes to the connector.

Babington Nebulizer (BN)

The BN is made of PEEK (polyetheretherketone), which resists almost all acid

and alkali solutions except for concentrated H

. This nebulizer allows the

introduction of higher matrix samples such as seawater, because of its large

sample orifice. The principle of nebulization is very simple: there are two

holes for sample and carrier gas lines, the sample (delivered by a peristaltic

pump) comes out of the upper hole and the carrier gas comes out of a small

orifice below the sample hole and nebulizes the sample. The Ar gas supply