Ion Trap - an LC/MS(n) system

The Agilent 6300 Series IonTrap mass spectrometer LC/MS consists of these components:

• interface to generate ions

• ion optical elements to guide the ions from the interface to the mass analyzer (ion trap)

• ion trap to collect the ions and then release them according to mass-to-charge ratio

• ion detector (and its electronics, firmware and software) to convert the ions to a mass spectrum

• vacuum pumps to keep the system at low pressure to ensure efficient ion transmission and detection.

The Ion Trap can operate with API (Atmospheric Pressure Interface) sources such as Electrospray Ionization (ESI).

The electrospray interface generates ions in a spray chamber. The system then transports and focuses the ions into the ion trap mass analyzer. Ion formation in API-electrospray occurs through more than one mechanism. If the chemistry of analyte, solvents, and buffers is correct, ions can be generated in solution before nebulization. (read more)

Sample inlets. You can introduce samples into the Trap mass spectrometer via delivery systems that differentiate themselves primarily by the liquid flow rates for which they are designed:

• LC system with quaternary, binary or isocratic pump

• LC system with capillary pump

• LC system with nano pump

• Syringe pump

• Capillary electrophoresis.

HPLC system

A High Peformance Liquid Chromatography (HPLC, or simply LC) system is the most common form of sample delivery for the Ion Trap. The Ion Trap electrospray interface (ESI) accepts flow rates up to 1 mL/min. With the Atmospheric Pressure Chemical Ionization (APCI) option, flow rates up to 2 mL/min. are possible.

You can operate the LC system in several modes with the Ion Trap. Typical modes include standard LC analysis, analysis without LC separation (flow injection analysis, FIA) and combined flow with the low-flow syringe pump.

Capillary electrophoresis (CE) is a migration of electrically charged compounds in solution under the influence of an applied electrical field. CE has the following special features:

• CE/MS compared to LC/MS provides different selectivity, higher separation efficiency and usually a shorter analysis time.

• Although CE/MS offers a greater mass sensitivity than LC/MS, its practical limits of detection are about 1000 times higher because of the lower mass loading capacity and dilution by the sheath liquid necessary for CE/MS operation.

• CE reduces sample preparation and analysis time for compounds in complex matrices, and MS/MS allows unambiguous identification.

• CE/MS(n) is suited for the analysis of compounds at ppm concentrations in small complex-matrix samples.

Thermal Desorption Unit TDU

The Thermal Desorption Unit (TDU) is a flexible automated solution for thermal desorption and thermal extraction.

Several techniques are supported by the TDU:

-Stir Bar Sorptive Extraction (SBSE) using the GERSTEL Twister®

-Dynamic Headspace (DHS) based on standard headspace vials

-Air sampling onto adsorbent tubes combined with thermal desorption

-Thermal extraction of solid samples placed in fritted TDU tubes

-Thermal extraction of liquids placed in µ-vials inside the TDU

-Direct introduction and thermal extraction of liquids such as standards

Cooled Injection System CIS

GERSTEL Cooled Injection System - internationally the most frequently used PTV-type universal inlet, with patented septumless sampling head.

Gas chromatographic analysis is now more versatile, reproducible and has lower detection limits than ever before, thanks to temperature programmed sample injection using GERSTEL Cooled Injection System.

Twister / Stir Bar Sorptive Extraction SBSE

The Gerstel-Twister allows analysis of organic compounds from aqueous matrices by Stir Bar Sorptive Extraction (SBSE): Faster than with conventional techniques, omitting time-costly preparation steps and solvents and up to 1000´ more sensitive than SPME. The GERSTEL-Twister looks like a conventional magnetic stirring rod, and works the same - except for one small difference: While it is stirring, it adsorbs and concentrates the organic contents onto its sorbent coating. It makes no difference if the carrier solution is drinking or waste water, body fluids or beverages.

GC-MSD System (EI-Quad: Electronic Impact coupled with Quadupole mass selector)

GCMS: Gas chromatography–mass spectrometry (GC-MS) is an analytical method that combines the features of gas-liquid chromatography and mass spectrometry to identify different substances within a test sample. The GC-MS is composed of two instruments: the gas chromatographer and the mass spectrometer.

The gas chromatographer utilizes a capillary column featured with different dimensions (lenght, diameter) as well as with diferent phase properties (chemical properties and thickness). The difference in the chemical properties between different molecules in a mixture and their relative affinity for the stationary phase of the column at different temperatures (or gradients) will promote separation of the molecules as the sample travels the length of the column.

The molecules are retained by the column and elute (come off) from the column at different times (called the retention time, RT). The mass spectrometer downstream captures, splits, ionizes, accelerates, deflects, and detects the ionized molecules and their fragments separately. The mass spectrometer does this by breaking each molecule into ionized fragments and detecting these fragments using their mass-to-charge ratio (m/z). The instrument output results in a chromatrogram with a third dimension represented by the recorded signals of the charged ions which together form the so called "mass spectrum".