INDUCTIVELY COUPLE PLASMA MASS SPECTROMETRY Research Technical Services

INDUCTIVELY COUPLE PLASMA MASS SPECTROMETRY

Inductively coupled plasma mass spectrometry (ICP-MS) is a technic used to determine most of the elements of the periodic table at trace and ultra-trace levels. The liquid sample is transported by a peristaltic pump to the nebulizer system where it is transformed into an aerosol thanks to the action of argon gas. The aerosol is led to the torch, where the plasma is generated. Temperatures of 8000 K can be reached inside the plasma. Under these conditions, atoms present in the sample are ionized / excited. Positive ions are transported inside the cuadrupolar analyser through an increasing vacuum interface where they are separated by its charge/mass ratio. Ions arrive to the detector and the abundance in the sample is evaluated.

Applications

Detection and quantification of most of the elements of the periodic table in a wide range of samples.

• Agriculture and foods

Determination of metals and contaminants in soils, pesticides, vegetables and foods in general.

• Clinical analysis

Determination of toxic elements in urine, blood, animal tissue, breast milk.

• Geology

Analysis of rare earths in sediments and rocks to determine its origin.

Evaluation of the pollution of soils.

Analysis of isotopic alterations of some elements

• Waters

Determination of metals in continental water, drinking water, waste water and sea water.

It also has the possibility to carry out semiquantitative determinations without the need of any standard. The instrument can run a scanning in all the range of masses providing information about all the elements of the periodic table.

Equipment

• Inductive coupling plasma mass spectrometer (ICP-MS), Agilent 7700x. This instrument provides the possibility of introducing samples with high content of dissolved solids such as sea water, without previous dilution. This is achieved with HMI (high matrix introduction) device which dilutes the aerosol with gas argon before reaching the interface avoiding problems of obstruction.

• Agilent 8900 triple quadrupole inductively coupled plasma mass spectrometer. This system has a tandem MS configuration, comprising two scanning quadrupole mass analysers either side of an octopole-based collision/reaction cell.

 Co-financed 50 % ERDF. Ministry of Science and Innovation (REF. PROYECTO: EQC2018-004065-P)

The ICP-MS 8900 extends the working range with respect to the 7700x model in the following aspects: 

• • It has the possibility of analyse organic matrix samples owing to an oxygen input previous to the plasma, which allows the removal of carbon deposits.
  • The existence of a quadrupole previous to the collision cell allows ions entering the cell to be selected with the consequent improvement in the detection limits of difficult elements.
  • The system works with the following cell gases: Helium (inert, configuration similar to the 7700x model), oxygen and hydrogen (reagents). The possibility of introducing reactive gases in the cell allows to control reactions between these gases and the analyte, displacing the measurement to masses free of interferences.
  •  Matrix Introduction (HMI/UHMI) technology uses aerosol dilution to reduce the sample matrix load on the plasma, allowing matrix levels up to several percent total dissolved solids (TDS) to be analysed routinely (25%).
  • Software includes different modules that allow specific analysis, such as isotopic dilution, coupling with liquid or gas chromatography for speciation, nanoparticle analysis in single particle mode or by coupling to Field Flow Fractionation, and cell analysis in mode “Single cell".

 O2 mode mass-shift method for measuring 75As. First cuadrupole (Q1) allows species with mass 75 to enter the cell where As reacts with oxygen to form 75As16O+. Possible interferences in mass 91 were eliminated in Q1.

 Sample requirements

• Samples must be delivered properly labelled, packed and conditioned to ensure their identification, integrity and conservation during the transport and guarantee the security of the personnel involved.
• The samples will be provided in acidic aqueous solution filtered at 0.45µm.
• Samples containing hydrofluoric acid will not be accepted.
• When analysis of complex matrix samples is required, information must be provided in LIMS application. Technicians will decide whether the analysis is carried out or not.
• Customers will provide as much data as possible concerning the sample (matrix different from HNO3 2%, high concentration of any element or compound that might interfere in the analysis, extreme pH and high content of dissolved solids, etc.).
• Samples will be delivered in 5 or 10 ml consecutively numbered tubes. Avoid complicated labels that may lead to confusion.