Today, accelerator mass spectrometry (AMS) technology enables us to carry out very precise measurements of radiocarbon (¹⁴C). Unfortunately, due to fluctuations in the ¹⁴C calibration curve, the resulting calibrated time intervals vary from decades up to centuries in calibrated age. Within a time scale of several decades, we can find several time intervals on the ¹⁴C calibration curve which correspond with periods of rapid increases in atmospheric ¹⁴CO₂ activity. Some of these “high slope” parts of the calibration curve could be used for fine time resolution for radiocarbon dating of individual samples. Nevertheless, there are certain limitations owing to the properties of the samples measured. We have prepared a time-resolution curve for the ¹⁴C dating method, applying calibration curve IntCal13 and assuming an uncertainty of ¹⁴C analyses ±15 yr BP (for recent samples). Our curve of the time resolution covers the last 50 ka. We found several time intervals with time resolution below 50 yr BP for the last 3 ka. Several time intervals which can enable substantially better time resolution compared to neighboring parts of the calibration curve were also found for periods older than 3 ka.

When human remains are found, apart from helping explain the cause of death and determining the extent of any injuries, forensic pathologists are usually requested to determine the identity of the deceased and how much time has elapsed since his death. In the Czech Republic, the criminal liability for murder is set to a statute of limitations of 20 years. In our pilot study, tissue samples of human remains from two decedents were radiocarbon (¹⁴C) dated to estimate the date of death. In agreement with published literature, we have confirmed relatively short carbon turnover time in hair, nail, and bone fat. Therefore these samples are the most appropriate for determining date of death. Other samples, such as teeth (collagen and carbonate form) and collagen isolated from bone samples, which exhibit relatively long carbon turnover time, can be used to reduce ambiguity of dating results and to indicate some interfering influences. Given the possibility of processing multiple sample types, we also propose brief guidelines for comparing and interpreting the results of individual analyses.

Regional levels of radiocarbon have been monitored in order to investigate the impact of fossil fuel combustion on the activity of atmospheric ¹⁴CO₂ in central Europe. Data from atmospheric ¹⁴CO₂ monitoring stations in the Czech Republic, Slovakia, and Hungary for the period 2000–2008 are presented and discussed. The Prague and Bratislava monitoring stations showed a distinct local Suess effect when compared to the Jungfraujoch clean-air monitoring station. However, during the summer period, statistically insignificant differences were observed between the low-altitude stations and the high-mountain Jungfraujoch station. ¹⁴C data from the Hungarian monitoring locality at Dunaföldvár and the Czech monitoring station at Košetice, which are not strongly affected by local fossil CO₂ sources, indicate similar grouping and amplitudes, typical for a regional Suess effect.

Fossil CO₂ emissions have been diluting the global ¹⁴C/C ratio of atmospheric CO₂ (Suess effect). We estimated the ¹⁴CO₂ amount in the atmosphere (and its trend) utilizing the calculated ¹⁴CO₂ activity concentration in the atmosphere (a_acn, reported in mBq m^–3). This parameter, calculated from Δ¹⁴CO₂ and the CO₂ mixing ratio (reported in micromoles of CO₂ per mole of air), is connected with the ¹⁴CO₂ quantity in the volume or mass unit of air, which is not influenced by the Suess effect. This parameter can only be influenced by processes linked to ¹⁴CO₂ emissions/uptake, e.g. associated with atmosphere-biosphere or atmosphere-ocean CO₂ exchange as well as by anthropogenic emissions of ¹⁴CO₂. Results obtained from measurements at Schauinsland station, Germany, indicate a stable amount of ¹⁴CO₂ in the atmosphere since the early 1990s.