Seachem Reef Status Strontium Test Kit

Accurately determine strontium levels in your reef aquarium. Seachem Strontium Test Kit has been revised to offer a dramatic decrease in the amount of time necessary to complete a strontium test. The former 45 minute to 1 hour process has been shortened to a mere 10 minutes. Reef Status Strontium Test Kit measures strontium by first separating the strontium in the sample water by chemical precipitation and filtration, followed by a sensitive titration process. Contains 50 titration tests for strontium, precise to 0.5 mg/L.

Please click on "More Information" for directions for use.

1. Pre-wet:
   Rinse the non-graduated pipette with de-ionized water. Then use the pipette to fill the separation column with de-ionized water to the 1 mL (cc) mark. Then use the provided column plunger to rapidly expel this water. You can bottom the plunger out, but do not press with extreme force. This step pre-wets the separation column and enables rapid filtration. If your separation column is still damp from previous tests (within 48 hours) you can skip this step.

   Attention: It is recommended to wear the supplied gloves and goggles (unless you wear glasses) for Steps 2 and 3 when handling Strontium #1.

2. Adsorption:
   • Use the graduated pipette to measure out 1 mL (top line) of sample. Place this sample in the sample vial. Fill the non-graduated pipette to the base of the bulb (0.25 mL) with Strontium #1 and add to the sample in the sample vial. Strontium #1 is a strong acid; therefore, use extreme caution when handling it. Always keep the cap on the bottle when not in immediate use and always keep the bottle in the box for maximum safety in case of a spill.
   • Firmly attach the collection vial cap to the collection vial and insert the separation column into the collection vial cap.
   • Using the non-graduated pipette, transfer the sample in the sample vial to the separation column (if all does not fit, wait until enough sample has dripped through such that you can place the remainder onto the column).

   Do not push the sample through. Allow it to drip until no more sample water is seen above the top of the column. If the sample stops dripping before done, you may give it a short push with the column plunger, then withdraw the plunger and allow to finish dripping.

3. Wash:
   While the sample is still dripping in Step 2 you can go ahead and prepare the wash solution. First, rinse the sample vial and both pipettes with de-ionized water. Repeat Step 2a using de-ionized water in place of the sample. Next, repeat Step 2c (using the wash solution you just prepared and waiting until Step 2c above is complete) except that now you can use the supplied column plunger to push this wash solution through rapidly (typical push-through time per full column is < 5 seconds). Once all of this wash solution has been pushed through, pump the plunger a few times to expel any residual water. When done, discard the material collected.

4. Elution:
   Rinse both vials, and the non-graduated pipette thoroughly with de-ionized water. Next, use the non-graduated pipette to transfer de-ionized water to the separation column. Then use the column plunger to push the water through rapidly (typical push-time per full column is < 5 seconds) and into the sample vial. Continue adding de-ionized water and pushing through until the sample vial is full to the top. Pour the contents of the sample vial into the collection vial when done.

5. Reagents:
   • Add 1 scoop of Strontium #2 (powder) and mix gently to dissolve.
   • Add 2 drops of Strontium #3 and mix.
   • Add 1 drop of Strontium #4 and mix*.
   • Add 1 drop of Strontium #5 and mix.
   • Let sit for 2 minutes. If strontium is present the solution will turn pink or purple. Pink indicates high strontium concentration; purple, a moderate amount; and a blue color indicates no strontium is present.

   *After performing Step 5c, note the blue color of the sample. It should very closely match the blue on the color chip (these are the same color, one is simply darker; both are provided to facilitate color matching without any confusion over color saturation). Occasionally this blue may be slightly darker or slightly different shades, if so, then note the blue color seen and titrate (Step 6) until you have matched this blue most closely.

6. Titration:
   Fill the syringe with Strontium Titrant to the 1 mL (cc) level. Then hold the syringe upright and tap any air bubbles to the tip; expel the bubbles by gently pushing on the syringe plunger. Then reinsert the syringe into the titrant and bring it to the 1 mL level.

Place the collection vial on the white square of the color chip provided and titrate with the syringe (i.e. dispense titrant solution to the contents of the collection vial from Step 5) until the color most closely matches either of the two blues on the color chip (or as noted in Step 5c).

Gently shake the collection vial after each drop. Once a color match is obtained, withdraw into the syringe any titrant hanging from the tip of the syringe so that the titrant is flush with the tip. If you're not sure if you have reached the endpoint, add 2 or 3 more drops. If you see no substantial change in color then you were at the endpoint. In this case, you would take the reading when you first noted no more change in color. Read dispensed volume from the "cc" side of the syringe and compare with the chart on the reverse to determine strontium level.

Reference Test
The proper performance of this kit may be validated by running a test in the normal manner except that the reference sample is used in place of an aquarium sample. It is not necessary to run a reference test to use this kit. The only time you might choose to run a reference test is if you have cause to believe the test is giving incorrect results. If you run a test using the reference sample and obtain the correct result (based on the known reference value provided) then you know the test is giving correct results. To run a reference test use the Strontium Reference as the sample. Reference value is listed on the container label.

Interpretation
This kit is capable of at least 50 strontium determinations and is designed specifically for seawater. The sample is treated and filtered through an adsorbent to selectively remove the strontium from solution. The filtrate is discarded and the adsorbent is washed to remove residual sample. The strontium is then eluted from the adsorbent and measured.

Natural seawater concentration for strontium is approximately 8 mg/L. By contrast, magnesium is present at about 1,300 mg/L and calcium at about 400 mg/L; together they exceed strontium by over 200 fold. Magnesium and calcium are chemically quite similar to strontium; thus, the measurement of strontium in the presence of high concentrations of magnesium and calcium with this kit requires meticulous attention to the instructions. To get the correct perspective, imagine that you are trying to find and count 8 lavender marbles in a jar containing 1,300 purple and 400 magenta marbles.