Status report of the Trondheim Radiocarbon Laboratory

Abstract

The Trondheim radiocarbon (14C) laboratory has evolved from a traditional radiocarbon decay counting laboratory to an accelerator mass spectrometry (AMS) facility primarily measuring 14C. This evolution required adjustments in sample preparation and data handling to match the capacity of the AMS system and reduction in sample sizes to about 1 mgC. We summarize here the steps involved in dating a sample at the National Laboratory for Age Determination in Trondheim, Norway. These include the structure of our sample database for information handling, sample cleaning procedures for different sample types, our reduction systems, both an automated EA-based system for regular use and a manual system for more challenging samples, and data evaluation. We will also briefly summarize the capabilities of our isotope-ratio mass spectrometer.

Multi-isotope variation reveals social complexity in Viking Age Norway

“…The same collagen extraction process was used for both radiocarbon determination and analysis by isotope ratio mass spectrometry (IRMS). Extraction was undertaken using a modified Longin method as per the protocols outlined in Seiler et al. (2019) at the Trondheim Radiocarbon Laboratory ( Longin, 1971 ; Seiler et al., 2019 ).…”

A dated volcano‐tectonic deformation event in Jan Mayen causing landlocking of Arctic charr

“…Collagen was extracted from bone samples. The resulting material was prepared and measured according to Seiler et al (2019). Radiocarbon ages are given as conventional ages relative to 1950 (Stuiver and Polach, 1977).…”

Radiocarbon Calibration around AD 1900 from Scots Pine (Pinus Sylvestris) tree rings from Northern Norway

“…This involves Soxhlet extraction with petroleum ether and ethanol to remove resins and other easily extractible compounds, and treatment with acid hypochlorite, sodium hypochlorite, sodium sulfite, and 17.5% sodium hydroxide to extract alpha-cellulose. Sixteen of the samples were cellulose extracted by using a base-acid-base-acid-bleaching method (BABAB; Seiler et al 2019;Němec et al 2010), which involves treatment with 4% sodium hydroxide, followed by short steps of 4% hydrogen chloride, 4% sodium hydroxide, and then 4% hydrogen chloride again at 75°C. A bleaching step with a mixture of 5% sodium chlorite and 4% hydrogen chloride at 75°C (pH ≤ 4), with an ultrasonic bath at room temperature, follows at the end.…”

“…After pretreatment, the cellulose was combusted in an elemental analyser (Elementar Microcube), and the CO 2 was reduced to graphite by H 2 gas over a Fe catalyst in an automated reduction system described by Ohneiser (2006). Seiler et al (2019) detail the procedures for sample treatment and graphitization. The 14 C/ 12 C ratio in the graphite was measured in the 1MV AMS system at the National Laboratory for Age Determination in Trondheim (Nadeau et al 2015).…”

“…Each wheel usually contains 10 (minimum eight) primary standards, five secondary standards, five process and machine blanks and 30 unknown samples. The blank correction was made assuming a modern contamination scaling inversely with the mass of the sample combusted (Seiler et al 2019). The process blank curve was derived from measurements of coal samples of different weights and measured over a few years as described by Seiler et al (2019).…”