Table of Contents
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Rock samples are prepared for ICP analysis using the following procedures on each sample:
- Cut to size (see Cutting Samples to Size below)
- Polish (see Polishing Samples on Diamond Wheel below)
- Clean (see Cleaning Samples below)
- Dry (see Drying Samples below)
- Crush (see Crushing Samples in the X-Press in XRD Sample Preparation Hard Rock )
- Grind (see Grinding Samples in the Shatterbox in XRD Sample Preparation Hard Rock)
Cutting Samples to Size
To cut samples for the X-Press, use the splitting room rock saws (located in the Core Deck) following these guidelines:
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Post-ignition measurements should be taken soon (within an hour) after removing crucibles from the furnace. Failure to do so will disrupt the LOI values. Reweigh the crucible plus the ignited sample to determine how much weight was gained or lost. Follow the same weighing procedure as in Pre-ignition Weighing.
- Record the final weight in the excel spreadsheet under 'CRUCIBLE + IGN SAMPLE WT'. The spreadsheet will populate the columns 'Post Ignition Loss' and '%LOI'.
- The formula used to calculate LOI is:
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Copy and paste your spreadsheet into that uploader. Click the 'Edit' button and 'Validate Sheet'. This checks and highlights any errors that need to be fixed. When the spreadsheet comes up clean, click 'Lims' and 'Upload'. The sheet will turn green when the measurements are successfully uploaded. The data is now in LIMS under Chemistry > ICP-AES Solids >Expanded LOI.
Cleaning the Quartz or Alumina Ceramic Crucibles
- Wash the crucibles with DI water and a small piece of a scouring pad (no soap).
- Rinse several times with DI water.
- Place crucibles in a 10% HNO3 bath for 12 hr. If in urgent need, the quartz crucibles can be soaked a minimum of 2 hours, but extra flux blanks will need to be made and added to batches that use these crucibles.
- Rinse the quartz crucibles 3 times with DI water after the acid bath. For the ceramic crucibles, rinse 3 times with DI and then soak them in a large beaker of DI water for 4-6 hours to dilute the acid absorbed by the crucibles.
- Dry the either type of crucibles in the oven at a maximum temperature of 60°C. For the ceramic crucibles, heat them to 800°C in the muffle furnace for 2 hours and allow to cool to room temperature before removing.
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Figure 43. Fused glass bead.
- An analytical procedural blank of Flux is prepared identically to the samples. The 0.4 g of flux (the pre-weighed flux) is fused with 10µL 0.172 mM of LiBr and dissolved. An additional 0.1 g of flux is NOT added to mimic the TDS of the 0.5 g mix of sample + flux because this would provide an inaccurate quantitation of the impurities introduced by the amount of flux used in preparation of the unknowns.
Weighing the Sample
Note: This process is typically done by the chemistry technicians.
Weighing the sample is a critical step. The sample weight should be as close to 100 mg as possible. Inaccuracies in the weight will show up in the analytical results. Print small labels for each sample and place on your small, clear capped vial. On the lid label a sticker with the core, section, and interval. Confirm with scientists what powder you will be using Fresh or Ignited.
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- Lay a large Kim wipe and a piece of weigh paper down next to the Bead Maker. Unwrap a platinum crucible and place it on the weigh paper. Pour the powder mix into the crucible. The sample should evenly cover the bottom.
- Pipette 10 µL of 0.172 mM LiBr wetting agent into the center of the sample powder.
- Open the Bead Maker lid and place sample inside the sample holder. The short wide crucible will fit directly; whereas, the tall narrow crucible will need an additional ceramic ring (no longer have these?).
- Close the lid. Double check both indicator lights are on. Press 'On' to start the program. The process will take 12 minutes and the sample is heated in three stages:
- Stage 1:700°C for 2 min
- Stage 2:1050°C for 5 min,
- Stage 3: 1050°C in agitation for 5 min.
- Be prepared to remove the crucible as soon as the timer reaches 0. The material hardens very quickly so be ready with safety glasses, gloves, and the platinum tipped tongs before the final stage has finished.
- With the Pt-tipped tongs, lift out the crucible and swirl the contents around to get the entire sample into one bead. Wear eye protection! The bead is very hot and rapid cooling can cause it to shatter and fly out.
- Place the crucible on its cooling rack. When seated properly the red light behind it will start flashing. When the beadmaker beeps it should be finished cooling.
- Place a sheet of 6x6 weigh paper on the ceramic plate. Take crucible from the cooling rack and prepare to flip it upside down on the paper to extract the bead.With crucible in hand flip over and give it a firm whack on the weigh paper. The bead should pop off without much resistance. Put gently tap the bottom of the crucible on the ceramic plate until the bead releases from the crucible. If the bead is stuck, tap the base of the crucible at different angles on the ceramic plate gently. Do not hit the rim of the crucible on the ceramic plate. The platinum is malleable and can easily be damaged if too much force is used.
- When the bead is loose in the crucible, tip the bead out of the crucible on to the weighing paper and then put the bead back into the vial that contained the flux/sample mixture.
- If there are small pieces of bead left behind you can use your Teflon spatula to try pry it off. Do not use too much force. The platinum is malleable and will get scratched and damaged if put under too much force. If it still remains, make a note of the sample number and inform the chemistry technician. The residue (if any) should come off during the cleaning process.
- Repeat process for all samples.
- Hand off all beads to the chemistry technicians to continue on with the ICP analysis.
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- Rinse crucibles with DI water.
- If beads are stuck to the bottom, sonicate with DI water for 30 min or more.
- Place crucibles in HNO3 10% bath for 12 hr. If you notice any signs of residue, leave in the acid bath for longer. If the crucibles are in urgent need, a minimum cleaning time in the HNO3 10% acid bath is 2 hrs, however, extra flux blanks should be made with these crucibles for analysis to ensure there isn't leftover contamination.
- Clean a Tupperware container with isopropyl alcohol. Lay down sheets of paper towel and large Kimwipes.
- Take crucibles out of the acid bath and rinse with DI water 3 times. Place crucible in the container. If the crucibles require polishing, see Polishing the Platinum Crucibles.
- Cover all crucibles with a large Kimwipe and place in the drying oven in the Chemistry Laboratory. Leave overnight.
- When dry remove crucibles and bring into the XRD laboratory. Wrap each crucible in a small Kimwipe and and place back in the safe. Lock the safe after all crucibles have been put back.
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| ANALYSIS | TABLE | NAME | ABOUT TEXT |
| LOI | SAMPLE | Exp | Exp: expedition number |
| LOI | SAMPLE | Site | Site: site number |
| LOI | SAMPLE | Hole | Hole: hole number |
| LOI | SAMPLE | Core | Core: core number |
| LOI | SAMPLE | Type | Type: type indicates the coring tool used to recover the core (typical types are F, H, R, X). |
| LOI | SAMPLE | Sect | Sect: section number |
| LOI | SAMPLE | A/W | A/W: archive (A) or working (W) section half. |
| LOI | SAMPLE | text_id | Text_ID: automatically generated database identifier for a sample, also carried on the printed labels. This identifier is guaranteed to be unique across all samples. |
| LOI | SAMPLE | sample_number | Sample Number: automatically generated database identifier for a sample. This is the primary key of the SAMPLE table. |
| LOI | SAMPLE | label_id | Label identifier: automatically generated, human readable name for a sample that is printed on labels. This name is not guaranteed unique across all samples. |
| LOI | SAMPLE | sample_name | Sample name: short name that may be specified for a sample. You can use an advanced filter to narrow your search by this parameter. |
| LOI | SAMPLE | x_sample_state | Sample state: Single-character identifier always set to "W" for samples; standards can vary. |
| LOI | SAMPLE | x_project | Project: similar in scope to the expedition number, the difference being that the project is the current cruise, whereas expedition could refer to material/results obtained on previous cruises |
| LOI | SAMPLE | x_capt_loc | Captured location: "captured location," this field is usually null and is unnecessary because any sample captured on the JR has a sample_number ending in 1, and GCR ending in 2 |
| LOI | SAMPLE | location | Location: location that sample was taken; this field is usually null and is unnecessary because any sample captured on the JR has a sample_number ending in 1, and GCR ending in 2 |
| LOI | SAMPLE | x_sampling_tool | Sampling tool: sampling tool used to take the sample (e.g., syringe, spatula) |
| LOI | SAMPLE | changed_by | Changed by: username of account used to make a change to a sample record |
| LOI | SAMPLE | changed_on | Changed on: date/time stamp for change made to a sample record |
| LOI | SAMPLE | sample_type | Sample type: type of sample from a predefined list (e.g., HOLE, CORE, LIQ) |
| LOI | SAMPLE | x_offset | Offset (m): top offset of sample from top of parent sample, expressed in meters. |
| LOI | SAMPLE | x_offset_cm | Offset (cm): top offset of sample from top of parent sample, expressed in centimeters. This is a calculated field (offset, converted to cm) |
| LOI | SAMPLE | x_bottom_offset_cm | Bottom offset (cm): bottom offset of sample from top of parent sample, expressed in centimeters. This is a calculated field (offset + length, converted to cm) |
| LOI | SAMPLE | x_diameter | Diameter (cm): diameter of sample, usually applied only to CORE, SECT, SHLF, and WRND samples; however this field is null on both Exp. 390 and 393, so it is no longer populated by Sample Master |
| LOI | SAMPLE | x_orig_len | Original length (m): field for the original length of a sample; not always (or reliably) populated |
| LOI | SAMPLE | x_length | Length (m): field for the length of a sample [as entered upon creation] |
| LOI | SAMPLE | x_length_cm | Length (cm): field for the length of a sample. This is a calculated field (length, converted to cm). |
| LOI | SAMPLE | status | Status: single-character code for the current status of a sample (e.g., active, canceled) |
| LOI | SAMPLE | old_status | Old status: single-character code for the previous status of a sample; used by the LIME program to restore a canceled sample |
| LOI | SAMPLE | original_sample | Original sample: field tying a sample below the CORE level to its parent HOLE sample |
| LOI | SAMPLE | parent_sample | Parent sample: the sample from which this sample was taken (e.g., for PWDR samples, this might be a SHLF or possibly another PWDR) |
| LOI | SAMPLE | standard | Standard: T/F field to differentiate between samples (standard=F) and QAQC standards (standard=T) |
| LOI | SAMPLE | login_by | Login by: username of account used to create the sample (can be the LIMS itself [e.g., SHLFs created when a SECT is created]) |
| LOI | SAMPLE | login_date | Login date: creation date of the sample |
| LOI | SAMPLE | legacy | Legacy flag: T/F indicator for when a sample is from a previous expedition and is locked/uneditable on this expedition |
| LOI | TEST | test changed_on | TEST changed on: date/time stamp for a change to a test record. |
| LOI | TEST | test status | TEST status: single-character code for the current status of a test (e.g., active, in process, canceled) |
| LOI | TEST | test old_status | TEST old status: single-character code for the previous status of a test; used by the LIME program to restore a canceled test |
| LOI | TEST | test test_number | TEST test number: automatically generated database identifier for a test record. This is the primary key of the TEST table. |
| LOI | TEST | test date_received | TEST date received: date/time stamp for the creation of the test record. |
| LOI | TEST | test instrument | TEST instrument [instrument group]: field that describes the instrument group (most often this applies to loggers with multiple sensors); often obscure (e.g., user_input) |
| LOI | TEST | test analysis | TEST analysis: analysis code associated with this test (foreign key to the ANALYSIS table) |
| LOI | TEST | test x_project | TEST project: similar in scope to the expedition number, the difference being that the project is the current cruise, whereas expedition could refer to material/results obtained on previous cruises |
| LOI | TEST | test sample_number | TEST sample number: the sample_number of the sample to which this test record is attached; a foreign key to the SAMPLE table |
| LOI | CALCULATED | Top depth CSF-A (m) | Top depth CSF-A (m): position of observation expressed relative to the top of the hole. |
| LOI | CALCULATED | Bottom depth CSF-A (m) | Bottom depth CSF-A (m): position of observation expressed relative to the top of the hole. |
| LOI | CALCULATED | Top depth CSF-B (m) | Top depth [other] (m): position of observation expressed relative to the top of the hole. The location is presented in a scale selected by the science party or the report user. |
| LOI | CALCULATED | Bottom depth CSF-B (m) | Bottom depth [other] (m): position of observation expressed relative to the top of the hole. The location is presented in a scale selected by the science party or the report user. |
| LOI | RESULT | crucible_and_postignition_sample_mass (g) | RESULT post-ignition crucible and sample mass (g): mass of the sample plus the crucible after ignition ("ashed") |
| LOI | RESULT | crucible_and_preignition_sample_mass (g) | RESULT pre-ignition crucible and sample mass (g): mass of the sample plus the crucible before ignition |
| LOI | RESULT | crucible_number | RESULT crucible number: number of the crucible used for this measurement |
| LOI | RESULT | crucible_preignition_mass (g) | RESULT crucible preignition mass (g): mass of the empty crucible before ignition |
| LOI | RESULT | loi_percent | RESULT loss on ignition (wt%): loss of material after ignition |
| LOI | RESULT | reference_mass (g) | RESULT reference mass (g): field for the reference mass used on the reference balance (not always populated) |
| LOI | RESULT | ssup_asman_id | RESULT spreadsheet uploader ASMAN_ID: serial number for the ASMAN link for the spreadsheet uploader file |
| LOI | RESULT | ssup_filename | RESULT spreadsheet uploader filename: file name for the spreadsheet uploader file |
| LOI | SAMPLE | sample description | SAMPLE comment: contents of the SAMPLE.description field, usually shown on reports as "Sample comments" |
| LOI | TEST | test test_comment | TEST comment: contents of the TEST.comment field, usually shown on reports as "Test comments" |
| LOI | RESULT | result comments | RESULT comment: contents of a result parameter with name = "comment," usually shown on reports as "Result comments" |
Archived Versions
ICP Sample Prep User Guide: 29th September 2022
LMUG-ICPPreparation-230220-1915-158.pdf
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