Spectroscopy and Impedance laboratory

Gas chromatography coupled to mass Spectrometer GC-MS

The gas chromatograph coupled with mass spectrometer GC-MS Q-TOF (Agilent Technologies 7890B GC System/7200 Accurate-Mass Q-TOF MS) is a complex equipment that allows the performance of high sensitivity qualitative and quantitative analyzes, having a wide dynamic range that allows the identification and quantification of compounds at the trace level.

The GC-MS Q-TOF system is composed of the following: gas chromatograph - Agilent 7890B with an operating panel that consists of the display, status lights, and keypad, vacuum system, Removable ion source (RIS) which allows quick change from EI to CI ion source, flight tube (TOF), mass filter quadrupole, collision cell and detector.

The high-resolution GC/Q-TOF enables accurate mass screening by GC/MS and enhanced compound identification through MS/MS, low-energy electron ionization, and complimentary chemical ionization techniques. The major advantage of Q-TOF technique is related to the possibility of obtaining a detection limit at very low values.

The major advantage of Q-TOF technique is related to the possibility of obtaining a detection limit at very low values.

There are three major steps involved with separating and identifying components of a mixture using a GC. They are:

Injecting a sample into the GC. (This takes place at the inlet.)
Separating the sample into individual components. (This takes place inside the column in the oven.)
Detecting what compounds were in the sample. (This is done in the detector.)
MS / MS "All Ions" technique allows undirected screening and quantification due to obtaining selective data

Main performance characteristics of the instrument:

due to its high-resolution and accurate mass data, the occurence of false positive results is reduced
Acquisition rates up to 50 Hz allow even the narrowest chromatographic peaks to be analyzed with full scan spectra. Fast acquisition speed and accurate mass facilitate deconvolution of coeluting GC peaks that are inseparable by low resolution MS
Agilent Nist library offers mass spectral information, formula determination and compound identification, in order to obtain a high degree of conformity assessment.
using MS/MS analysis, the chemical structure of the compounds is presented
ensures performance such as reproducibility of retention times and reproducibility of areas
Performs screening, profiling, discovery workflows, and more, using comprehensive MassHunter software
Detects trace-level target compounds in the presence of more abundant matrix compounds with a wide in-spectrum dynamic range
MS / MS "All Ions" technique allows undirected screening and quantification due to obtaining selective data

The equipment can be used for concentration determination of organochlorine and organophosphorus pesticides from different plants, fruits, drinking water or food. Through developed screening methods, compounds from various cosmetic extracts and essential oils can be separated and identified.

Gas chromatography coupled with mass spectrometer to determine isotopic ratio

The system allows the analytical determination of isotopic ratios in a sample, a feature that helps establish the history of samples. NIST certified or NIST traceable standards with fixed isotopic distribution are used.

Among the potential applications of this type of spectrometry are the legal, food, pharmaceutical, allergen, biochemistry, metabolism and others. Main performance characteristics of the instrument: Conversion system for carbon, nitrogen and hydrogen Touch screen display with software that permits access and service and logging according to time deviations to pressure-tight tests by a single click; Reproducibility of the retention time (typical value) < 0,0008 min; Reproducibility of the peaks area (typical value) < 0,5% RSD;

Laser ablation inductively coupled plasma mass spectrometry

ICP-MS means inductively coupled plasma mass spectrometry and is a modern analytical technique used to detect a wide range of metals and non-metals at very low concentrations. The method is based on combining inductively coupled plasma as ionization method with mass spectrometry for ion separation and detection.

In the mass spectrometer, the ions are separated, and elements are identified according to their mass to charge ratio, m/z, concentration of the targeted element being proportional to the number of ions. The proportionality factor is determined by measuring calibration solutions.

ICP-MS 8800 Triple Quad Inductively Coupled Plasma Mass Spectrometer (Agilent Technologies) can be used with 3 types of sample introduction systems for specific applications:

Typically, samples are introduced into the ICP-MS by aspiration of a test solution obtained by pressure microwave digestion.
2. HPLC module, which allows the separation of different species of the same element by using a speciation column, being useful for analysis of Cr3 +/Cr6 +, As3 +/As6 +.
3. Laser ablation, which allows the analysis of constituent elements of solid samples without prior preparation, as well as the possibility of mapping the composition of constituent elements of a solid sample.

The typical system has the following main components:

1. Sample introduction system,consisting of:

Peristaltic pump with 10 rollers and 3 working channels, for the introduction of the solution in the nebulizer
Concentric glass nebulizer
Scott-double pass quartz spray chamber, with Peltier cooling in the range of -5…+20 °C, the temperature being controlled via MassHunter software

Torch with electromagnetic shielding system (Shield Torch) - allows controlled movement from software, automatic alignment and it allows easy access for maintenance. The shielding system between the coil and the torch reduces levels of (poly) atomic ions bound to argon (nebulizing gas), which can interfere with the determination of certain elements such as K, Ca and Fe.
Radiofrequency generator (27 MHz) which facilitates plasma power adjustment in the range of 500-1600 W
The ionic interface,where ions are transferred from plasma to the mass spectrometer, and consists of:

Sampling cone, made of Ni, with an orifice of 1 mm
Skimmer cone, made of Ni, with an orifice of 0.4 mm

Mass spectrometer, consisting of:

- Electronic lens system cu: with extraction lenses and deflection lenses that help remove neutral species and photons from the ion beam;

Collision / Reaction System - Octopole Reaction System (ORS)

Thermally stabilized ion-guided cell at a working frequency of 12 MHz
- He is used to eliminate interference using differentiation by kinetic energy and has a reactive mode of operation with the possibility of introducing through 4 separate lines with electronic control over the flow (variable up to 1 mL / min) of several types of gases: H2, He, Ar, O2, NH3;2, He, Ar, O2, NH3;
The ventilation of the cell and the transition from one gas to another is very fast (about 5 seconds);
The maximum switching time between gases is 5 seconds.

Mass analyzer

MS/MS tandem spectrometer configuration with two quadrupoles (each quadrupole has a hyperbolic profile of the bars and operates at a working frequency of 3 MHz)
it can work in the following modes: simple MS mode and MS/MS mode in which the first quadrupole will manage the target ions and the second quadrupole, the product ions
each quadrupole has the possibility to perform scans in the entire mass range (2 - 260 amu) or to work at fixed mass with a scanning speed >3000 amu /sec
the abundance sensitivity in MS mode is 5×10-7 (for small masses) and 10-7 (for large masses); the sensitivity in MS / MS mode is higher than 10-14.-7 (mase mici) și 10-7 (mase mari); sensibilitatea de abundență în modul MS/MS este mai înaltă de 10-14.

Detector

electronic multiplier with dual mode
allows automatic switching between pulse and analog mode
dwell time: 1000 microseconds (transient signals can be measured with an integration time below 100 microseconds in both pulse and analog mode)
the dynamic range is at least 9 orders of magnitude

The LC-ICP-MS interface contains:

Quaternary HPLC pump with pressure of 600 bar, flow accuracy <0.07% RSD with degasser and 5 built-in channels.
HPLC autosampler with 0.1-100 μL injection volume
LC-ICPMS coupling interface
speciation columns for Cr and As

Laser ablation system model LSX-266, manufacturer CETAC provided with:

Nd: YAG type laser with 266 nm UV operation, energy density> 22.5 J / cm2 (for an area of 200 μm) and 9000 J / cm2 (for an area of 10 μm);2 (pentru o arie de 200 μm) și 9000 J/cm2 (pentru o arie de 10 μm);

ICP-MS MassHunter working software:

simplified form with workflow guide.
automatic sequences.
predefined data acquisition modes for precursor and product ion scans.
save analysis method, configuration, corrections, system files, test files, results files.
the chromatographic software allows the integration of HPLC and ICPMS, instrument control, analysis sequence, chromatographic data analysis, periodic recalibration sequence updating, chromatographic retention times or ion ratio updating.

Common ICP-MS applications include:

determination of toxic elements in environmental matrices (surface water, wastewater, sludge)
determination of mineral elements (micronutrients) in food matrices.
determination of toxic metals in food matrices.

For research and teaching purposes, ICP-MS has also been used in applications such as:

quantitative assessment of metallic nanoparticles biodistribution in tissues

release profile of drugs that contain metals (cisplatin, carboplatin) from various synthesized (nano)materials.

Fourier-transform infrared spectrometer FTIR

The Thermo Scientific Nicolet iS50 system is a FTIR spectrometer with integrated features for performing a wide range of experiments and applications. The iS50 spectrometer performs chemical analysis of various materials by collecting data is the mid-IR, far-IR and near-IR spectral domain, using a variety of accessories that can be installed and used both in the spectrometer compartment and externally attached.

Each accessory has unique configuration parameters (parameters that are configured through the OMNIC software). It has several modules such as ATR (total attenuated reflection), NIR-IR module with Integrating Sphere and Fiber Optic connections, Raman and ATR with heating, which have a specific blue button associated.

The ATR device can easily provide information about the imprint of a pure compound or a mixture of compounds, comparing the result with a previous one is often a quick and easy way to verify a sample. The signal to noise ratio >55000 peak to peak, measured at a 4 cm-1 resolution by background collecting for 80 seconds, sample for 60 seconds, in the region of 2200-2100 cm-1 with purge. The system is equipped with FT-RAMAN module, with built-in XYZ sample stage.-1 .-1.

In addition to the built-in ATR device, the system the system has a mountable ATR with diamond crystal which can be heated up to 300°C.

Characteristics:

iS50 ATR module
Crystal	Diamond
Spectral range	80-5000 cm-1
Maximum pressure on the sample	60 lbs
Detector	DLaTGS
iS50 NIR module
Interior of Integrating Sphere	Covered with gold
Detector	InGaAs
iS50 Raman module
Laser	1064 nm diode
Laser power	>450 mW
Laser point size	60 micron

OMNIC software is used to collect, process and analyze spectral data. This software includes a database of 9000 compounds. The equipment is used for the analysis of different materials from research laboratories obtained from laboratory experiments, but also of materials / products obtained by collaborating with various institutions. The system is also used for the qualitative determination of food samples and the determination of food fats.

Equipment for the fast detection of protein, salt, fat, sugar and water in meat, cereals, milk and animal feed (NIR)

Main performance characteristics of the instrument:

Touch-screen display for rapid operation
The capacity to measure relevant parameters for each product (ash content in flour, humidity in flour, fat content in meats, fibre content in cereals, etc.)
Diode array – NIR detector, capable to acquire more than 100 spectra/sec
Rapid analysis (around 60 sec per sample, depending on the number of parameters and the desired precision)
The possibility to expand the catalogue of work methods of the instrument for free
The analysis does not require preparation of the sample, the sample is analysed in the state in which it is given
Large number of matrixes (barley, oats, fats, soy, canola, wheat, sunflower, dairy produce, yogurt, flour, sugar, etc.)
The instrument has a minimum of moving parts, it is robust and requires minimum maintenance

Nuclear magnetic resonance spectrometer

Main performance characteristics of the instrument:

2 T permanent magnet without liquid nitrogen cooling
Small size and high portability
Liquid sample injection, small sample volume (40 microliters)
Larmor operating frequency of 82 ± 2 MHz for the proton of the 1H nucleus
Resolution > 20 ppb
Signal to noise ratio > 4000:1 for water
The instrument does not specifically need the use of deuterated solvent for dilution, this being also possible in non-deuterated solvents (like chloroform)

Nuclear magnetic resonance spectroscopy is a powerful analytical technique that offers information regarding the mode in which atoms are bonded to one another in a molecule. Lately, amphetamine derivatives got popular due to the long lifetime interval from the discovery of a new compound to the moment in which that compound is made illegal and the slowness of current analytical methods.

The nuclear magnetic resonance technique in strong magnetic field is too expensive, but the one with low resolution permanent magnet can be a reasonable solution. A molecule has a specific print on the spectrum, any small modification to a functional group can be seen in the spectrum to prove that a molecule is an amphetamine derivative. Is valid in case of other derivatives of illegal substances that are introduced in various dietary supplements for their known effect, masked by the appearance of a plant extract mixture.

Spectroscopy and Impedance laboratory

Gas chromatography coupled to mass Spectrometer GC-MS

Gas chromatography coupled with mass spectrometer to determine isotopic ratio

Laser ablation inductively coupled plasma mass spectrometry

ICP-MS MassHunter working software:

Fourier-transform infrared spectrometer FTIR

Characteristics:

Equipment for the fast detection of protein, salt, fat, sugar and water in meat, cereals, milk and animal feed (NIR)

Nuclear magnetic resonance spectrometer

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