Measurement report
on cross-talk levels obtained using
EA desiccants: Sicapent, Wetsorber and Wetsorber S
Three different types of desiccants were used for water removal during the combustion of standard samples Ox2 (oxalic acid) and blanks (PhA – phthalic acid) in Elementar’s Elemental Analyzer. The aim of the measurement was to determine the amount of carbon transferred between consecutive samples and assess whether the material is a good fit for 14C-AMS sample preparation.
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\uD83E\uDD14 Problem
All elemental analyzers used in conjunction with Ionplus equipment should use a water trap to remove water from the carrier gas upon combustion. Until recently, the desiccant SICAPENT® was used for this purpose. Since the Sicapent material is no longer available on the market, the replacement is going to be either Wetsorber “Wetsorber” (calcium chloride) or Wetsorber S “Wetsorber S” (calcium chloride, aluminium oxide and magnesium perchlorate). How do the new materials compare when it comes to cross-talk in radiocarbon samples?
\uD83C\uDF31 Measurement
Three different types of desiccants were used for water removal during the combustion of overmodern samples OX2 (NIST SRM 4990C, oxalic acid) and blanks PHA (In house blank – phthalic anhydride) in Elementar’s elemental analyzer. The combustion sequence containing the samples weights is similar for all three materials, as in the below example :
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Therefore, 3 batches, each of 7 samples, corresponding to (Table 1).
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Therefore a batch of 7 samples was graphitized with each material: Sicapent, Wetsorber and Wetsorber S were graphitized and measured . The total of three batches were subsequently measured in the same magazine, using a MICADAS system. The amount of fraction modern carbon (or F14C ) found in the blanks (Figure 1), as well as the blank ages (Figure2), for each corresponding desiccant blank sample , were plotted as a function of its their position with respect to the Ox2previous OX2:
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🧐 Findings
We found that Wetsorber S has a reduced an even lower cross-talk, similar to or even better than Sicapentmaterial, and therefore, this is our recommendation to be used in EA systems involved in 14C applications.Wetsorber however is not recommended in applications for 14C analysis. An effect on the OX2’s was not observed.