Elemental analysis

Isotope Ratio Mass Spectrometer (IRMS) Sercon: HS2022 mass spectrometer; isoEArth+ elemental analyzer (for solids, solids dissolved in water, liquids and gases); high-temperature elemental analyzer HT-EA Wave (for solids and solids dissolved in water);

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Article 1: equipment and analysis general information

Module isoEArth+ elemental analyzer (for solids, solids dissolved in water, liquids and gases):

The isoEArth+ elemental analyzer is a high-performance system for the simultaneous quantification of Carbon (C), Nitrogen (N) and Sulfur (S) in solid, liquid and gaseous samples, integrable with isotope ratio mass spectrometers (IRMS) such as the HS2022 for precise isotopic ratio analyses. Solid samples are introduced into tin capsules (p/n SC0018 or SC0009), for solids dissolved in liquids they are loaded by autosampler into tin capsules with EMASorb B Granular (p/n SC0238), and gaseous or liquid samples are loaded using the XYZ autosampler coupled to the module which has a thermostabilizer, 6 mL glass vials with screw cap and septum (p/n SI0958B); they are then subjected to combustion in a programmable furnace generating gases such as CO₂, N₂ and SO₂ (and in the case of the XYZ autosampler also H₂) which are quantified by thermal conductivity detector (TCD) for elemental analysis and sent to the IRMS for isotopic determination. The system allows analysis of organic, inorganic and environmental matrices, following an automated sequence that includes sample preparation and loading, thermal decomposition, gas purification, isotopic analysis and calibration with standards.

HT-EA Module (for solids and solids dissolved in water)

The HT-EA module is a high-temperature elemental analysis furnace designed for the thermal decomposition of solid samples by combustion, pyrolysis or reduction, allowing precise measurement of stable isotopes of oxygen (¹⁸O/¹⁶O) and deuterium (D/H) in solid and liquid samples, integrating with isotope ratio mass spectrometers (IRMS) such as the HS2022. Solid samples are introduced into silver capsules (p/n SC0035), while liquid samples are loaded by autosampler into silver capsules with EMASorb B Granular (p/n SC0238), and subjected to high temperatures of up to 1450 °C, generating gases such as CO₂ and H₂ which are purified by chromatographic columns and quantified with a thermal conductivity detector (TCD) for elemental analysis prior to isotopic evaluation in the IRMS. For calibration of isotopic analyses, international oxygen and hydrogen standards are used, while helium acts as carrier gas, oxygen ensures complete combustion and hydrogen serves as TCD reference. The system allows analysis of organic, inorganic and environmental matrices, following an automated sequence that includes sample preparation and loading, thermal decomposition, gas purification, isotopic analysis and calibration with standards.

For more details on the equipment general information (consumables, materials and reagents it uses), send an inquiry to the laboratory's institutional email: laie.iimyc@mdp.edu.ar

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Article 2: Service request

1.- For researchers/fellows belonging to IIMYC:

The initial service management must be carried out exclusively through the IIMYC's Internal Tickets system:

www.IIMYC.gob.ar → IIMYC internal → service request → send ticket → "isótopos estables/TOC-L" CPA Agustina Pardini.

The request ticket must clearly specify the type of analysis required: Elemental analysis (H, O, N, C and/or S), as well as the corresponding sample type (solid, solids dissolved in water, gaseous). Likewise, a contact email address must be provided to facilitate communication with the LAIE.

2.- For service applicants external to IIMYC:

The initial management must be done by email (laie.iimyc@mdp.edu.ar or agustinapardini@mdp.edu.ar) with the subject "elemental analysis".

The body of the email must clearly specify the type of analysis required: Elemental analysis (H, O, N, C and/or S), as well as the corresponding sample type (solid, solids dissolved in water, gaseous).

Within a period not exceeding 72 hours, a response will be sent to the email indicated in the ticket query, along with an attached Excel file.

This file must be completed by the applicant and include, among other relevant fields, the work group data, the name of the responsible director, and the sample status in relation to the requested analysis.

Once the file is completed, it must be sent by email to the laboratory.

Subsequently, the corresponding budget will be delivered and sample reception will be coordinated.

These must be delivered to the LAIE, where the IRMS-SERCON equipment is installed, located at the UNMDP annex (former Illia), Av. Juan B. Justo 2250 ground floor, on the previously agreed date and time.

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Article 3: Service costs

The service is provided through a STAN (High-Level Technological Service) of CONICET.

The cost of the service depends on multiple factors, mainly the characteristics of the samples, the type of analysis requested and the treatment required for their preparation. The main elements that influence the price determination include:

  1. Sample preparation:

    • It is evaluated whether the samples are ready for analysis or if they require additional services, such as weighing with or without capsules.

    • if they are analyzed directly: whether it is analyzed directly or requires pre-treatment before analysis (e.g., use of acids to quantify carbonates/bicarbonates differentiated from organic carbon, etc.)

    • if they are considered "difficult samples": large particles or not completely pulverized that require additional analysis treatment. (use of vanadium pentoxide, p/n SC0027, as a catalyst in elemental analysis).

  2. Required analyses and element combinations: (check service availability)

    • Carbon (C), Nitrogen (N), Sulfur (S), NC simultaneously or NCS simultaneously.

    • Hydrogen (H), Oxygen (O) or HO simultaneously.

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Article 4: Analysis priority

If demand exceeds operational capacity, priority will be given to samples belonging to IIMyC.

Users are requested to review and prioritize the number of required analyses, in order to optimize the use of available resources and allow as many requests as possible to be processed.

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Article 5: submission of samples ready for analysis

Before preparing samples, the responsible CPA should be consulted about the appropriate procedure, as there may be exceptions to the general rule of the work protocol for the analysis.

1.- Solid samples and samples of solids dissolved in water:

For samples that have not been weighed and/or pressed, see the microbalance tab.

Tin (Sn) capsules are used: intended for elemental analysis and/or determination of isotopic ratios of carbon, nitrogen and sulfur.

Silver (Ag) capsules are used: used for elemental analysis and/or determination of isotopic ratios of oxygen and hydrogen.

a.- Organize the samples in a clean 96-well tray. Load the samples into rows and fill each one completely.

b.- Group samples of similar material (for example, place all animal tissue samples in sequential cells).

c.- Record the tray information, including the weight of the samples and empty capsules. The identifier for each sample must be unique and they must be consecutive to facilitate analysis.

d.- Tray names must be unique. Each service user will be assigned a single time an identification number, which must be mandatorily included on each tray sent. This procedure allows avoiding handling errors and cross-contamination of samples, situations that can lead to unreliable results.

Likewise, the year of shipment must be recorded together with the tray number, and the numbering of the trays must be consecutive, in order to facilitate long-term organization, traceability and retrieval of results.

e.- Secure small samples before closing the lid; do not use Parafilm or adhesive tape to cover the wells, as they are a source of contamination for the capsules. Close the lid tightly with adhesive tape on all four sides. Turn the tray over and shake it gently to check if the samples remain in the wells or if the capsules lose sample material. Recapsulate leaking capsules before shipping.

2.- Liquid samples:

The ISOearth+ module also has an autosampler for low-volume liquid samples, which allows, by generating the analyte of interest in its gaseous state:

  • Determine hydrogen using Pt as catalyst.

  • Analyze carbonates by transforming them into CO₂ by adding acids.

  • Analyze generated gaseous nitrogen.

a.- Organize the samples in a clean rack with test tubes previously muffle-furnaced at 360 °C for 20 minutes.

b.- Group samples of similar matrix.

c.- Record the rack information with the volume of sample sent. The identifier for each sample must be unique and they must be consecutive to facilitate analysis.

d.- Rack names must be unique. Each service user will be assigned a single time an identification number, which must be mandatorily included on each rack sent. This procedure allows avoiding handling errors and cross-contamination of samples, situations that can lead to unreliable results.

Likewise, the year of shipment must be recorded together with the rack number, which for organizational reasons will be referred to in the numbering as "tray". The numbering of the trays must be consecutive, in order to facilitate long-term organization, traceability and retrieval of results.

3.- Gaseous samples:

They require the use of sampling elements provided by the LAIE, which imply an additional cost due to wear and/or possible breakage.

The ISOearth+ module also has an autosampler for gaseous samples, which allows:

  • Determine hydrogen using Pt as catalyst.

  • Analyze carbonates by transforming them into CO₂ by adding acids.

  • Analyze gaseous nitrogen.

a.- The first thing you should do is consult about the vials available in the laboratory for this type of analysis.

b.- Organize the samples in a clean rack with the vials.

c.- Record the rack information. The identifier for each sample must be unique and they must be consecutive to facilitate analysis.

d.- Rack names must be unique. Each service user will be assigned a single time an identification number, which must be mandatorily included on each rack sent. This procedure allows avoiding handling errors and cross-contamination of samples, situations that can lead to unreliable results.

Likewise, the year of shipment must be recorded together with the rack number, which for organizational reasons will be referred to in the numbering as "tray". The numbering of the trays must be consecutive, in order to facilitate long-term organization, traceability and retrieval of results.

Example:
 Dr. Juan Pérez, from IIMYC, is assigned the identifier CCI-0001.
The trays sent during the year 2025 must be labeled as follows:

  • CCI-0001 – 2025 – Tray No. 0533

  • CCI-0001 – 2025 – Tray No. 0534

  • etc.

User identification numbers: they are composed of a prefix indicating the type of applicant and a correlative order number.

The established prefixes are as follows:

CCI: Scientific community of IIMyC + order number
CCM: Scientific community of UNMDP + order number
CCE: Scientific community external to UNMDP + order number
CP: Private applicants external to the scientific community + order number

This identification system allows proper sample traceability, avoids handling errors and facilitates the long-term organization and retrieval of analytical information.

Note: It is essential not to repeat the identification number of each tray, since the services will be recorded in a general database, with confidential and exclusive access of the LAIE. This system allows quickly locating and retrieving analytical results in the future, in response to any requirement or consultation need.