INSTRUCTIONS FOR  ¹⁴C SAMPLING

General

5 g of pure carbon is necessary for an analysis. The amount of sample depends on chemical composition, i.e. on the amount of carbon in material to be analyzed. The sample should be representative with known origin,location and all other relevant data. Samples should be clearly and uniquli identified. Sample submission should be accompanied by a filled-in Sample Form. It is very important to avoid any contamination during the sampling procedure, e.g. by mixing of different layers or by incorrect storing. Sampling does not require any special equipment (gloves or similar), but one should avoid contamination by any contemporaneous material (pieces of cotton wool, mould etc.). It is strictly forbidden to treat the sample with organic coat or colour. The best way is to put it into a plastic bag.
Sampling instructions are given for different material species.

Charcoal or similar

It is necessary to deliver about 10 to 15 g of dry charcoal sample. The samples should be cleaned mechanically from soil, rootlets and other admixtures as much as it is possible. They should be separated mechanically from soil admixtures as much as it is possible. If they are wet it is desirable to dry them and then put into the plastic bag. Wet samples cannot be stored in plastic bag for a longer time because of production of mildew which contaminates the sample. The bag should be closed and the sample identification should be put on it.

Wood

It is necessary to deliver about 20 to 30 g of dry sample. If the wood is wet it is desirable to dry it and then put into the plastic bag.  If the sample is a part of a trunk, tree rings should be identified if possible. Inner rings give the time when the tree started to grow and outer rings the time when it ceased growing. Sample can be in one piece or chopped.

Bones

It is necessary to deliver 200 to 500 g of bones, depending on the age (older bones contain less collagen, because collagen is subjected to partial destruction during the time). Bones of forearm (antebrachium), lower arm (brachium), femur or tibia are desirable. Bones should be separated mechanically from soil admixtures as much as it is possible. If they are moist it is desirable to dry them and then put into a plastic bag. Wet samples cannot be stored in plastic bag for a longer time because of production of mildew which contaminates the sample. The bag should be closed and the sample identification should be put on it.

Peat, soil

The amount of peat or soil depends on concentration of organic compounds, i.e. of carbon, in these samples. The necessary amount of sample is between 100 and 500 g  of dry material. Sample should be stored in a plastic bag with clear identificationof the sample. Wet sample should be dried on air and afterwards put into a bag. Otherwise mildew will contaminate the sample.

Biologic material (leaves, moss, grass)

The required amount is 300 to 500 g of dry sample. Sample should be stored in a plastic bag and the name (or code) of the sample should be written. Wet samples should be dried (also on air) and afterwards put into the bag. Otherwise the mildew will contaminate the sample.

Carbonate samples (speleothems, tufa, carbonate sediments, shells etc.)

It is necessary to submit 30-100 g of sample, depending on the amount of carbonates.  Sample should be stored in a plastic bag and the name (or code) of the sample should be written.

Water

The necessary amount of water depends on the concentration of dissolved bicarbonates. Minimal amount of water can be calculated according to the equation: V= 25000/(ppm "A"), where V represents water volume in liters and  ppm"A" is the amount of carbonates and bicarbonates (in mg/L). It is advisable to take 25% water in sufficiente. The amount of water usually ranges between 50L (mineral waters) and 200L. For groundwater is normally 100L enough. Water should be put in clean plastic 20 L or 25L canisters filled to the top and the name (or code) of the sample should be written. It is desirable to rinse the canister before filling with the same water sample.

Air (atmospheric CO₂)

CO2 is absorbed from the atmosphere in the saturated solution of sodium hydroxide (NaOH). 100 mL of saturated NaOH should be placed in a plastic tray of large area and should be covered by a fine-meshed plastic or metal grid, which prevents falling-in of any objects or small animals. The tray should be put on a selected place, often below a roof, and should be well marked in order to avoid the danger of aggressive effect of NaOH to the skin. Sample should be collected during a two or four-weeks period. The precipitated carbonate should be collected carefully by a plastic spoon into a plastic bottle, which should be closed and clearly identified. Caution: Handle NaOH with plastic gloves!
 

INSTRUCTIONS FOR  ³H SAMPLING

For measurement of tritium activity in liquid scintillation counter with electrolytic enrichment it is necessary to bring 700 mL of water sample. However, the amount of 1,5 L is advisable in order to enable repeating of measurement, if necessary.

Precipitation (rain, snow)

Collecting of monthly precipitation samples for isotopic analyses:

Precipitation shluld be collected by a rain gauge (ombrometer).

1. The daily amount of precipitation should be measured by a graduated bottle and recorded. The rain should be poured into 5L plastic canister which should be well tightened up. The rain should be collected in the canister during a month. In winter, snow should be melted, the amount of melted watermeasured, and poured into the canister. The canister should be kept on a cold and dark place out of the presence of radioactive sources (radioactive lightning conductors, smoke detectors or similar).
2. In case when the precipitation amount is not recorded daily, the water should be poured from the rain gauge (ombrometer) into the canister on the last day in a month. The amount of precipitation should be measured and recorded. If during the month there were heavy showers which could fill the rain gauge, it should be emptied more often.
3. On the last day in the month water from canister will be transferred into a plastic 700 mL bottle, which should be closed and stored in a cold and dark place out of the presence of radioactive sources.
4. The remaining water in the canister, if any, could be thrown away, if not needed for other purposes. The next sample can be collected in the same canister on the above explained way.

Groundwater and wells

In case of artesian wells water should be pumped for a while (15-20 min). A clean plastic or glass bottle should be rinsed by the sample, filled and closed. Sample name or code should be marked, as well as the sampling date.

REMARK

The unused rests of samples for 14C or 3H measurements will be thrown away after the measurement if not agreed otherwise upon submitting.