Hardware manual

6-8 Agilent 7500 Series ICP-MS Hardware Manual

6 Technical Information

Nebulizer Endcap

Each nebulizer has a dedicated endcap made of Teflon. Except for the CF, the

nebulizer can be removed from the endcap. The make- up gas is introduced

into the spray chamber through the endcap giving a tangential flow around the

nebulizer, except for the CF.

Spray Chamber

There are several types of spray chambers for ICP- MS. The most commonly

used type is the Scott double pass spray chamber, which is employed in the

Agilent 7500. The Agilent 7500 spray chamber is available in the following

materials:

• Quartz (QZ)

• Polypropylene (PP)

• Teflon (PFA)

The spray chamber is mounted in an aluminum block and cooled by a Peltier

thermoelectric module. The spray chamber temperature is maintained at 2 °C

for aqueous samples, and can go down to - 5 °C for organic solvents or higher

vapor pressure samples. When the spray chamber temperature is unstable,

water loading to the plasma is affected, causing signal instability. Higher spray

chamber temperatures increase the oxide ion level as well. A drain tube is

connected to the spray chamber by means of a special cap that allows easy

attachment and detachment.

Quartz (QZ)

The QZ is made of pure silica and it can be used for acids and organic solvents,

but not for HF or strong alkaline solutions. To reduce memory effects, soak the

QZ spray chamber in a 5% NH

OH (v/v) solution for 2 hours prior to use,

followed by washing with pure water.

Polypropylene (PP)

This spray chamber is mainly designed for analysis of samples containing HF.

It can also be used for other acids and alkaline solutions. For analysis of boron

at trace levels, the PP spray chamber is recommended. Only a few organic