PEARL

Water Sampling at PEARL

NOTE                                       
For important sample bottle  
 shipping methods, click here.

PEARL FIELD SAMPLING PROTOCOL AND TECHNIQUES FOR WATER CHEMISTRY ANALYSES
(Updated June, 2008)
(See bottle washing procedures at the bottom of this document) 

Things to remember:   

1.  Use pre-cleaned sample bottles (washed according to procedures as discussed at the bottom of this document).
2.  Filters for POC/PN (GFC 2.5cm) need to be pre-ignited at 525˚C for two hours in a muffle furnace before taking them to the field.  Do this by making a little aluminium foil tray, spreading the filters out in a single layer (using tweezers), and bringing them to 525˚C for two hours.  When done, use tweezers to re-stack filters (do not bend or fold), and wrap them inside the pre-ignited aluminium foil.
3. Rinse the pre-cleaned sample bottles and lids with lake water 3 times prior to filling them at each site (if sampling for unfiltered water parameters).
4. Touch only the outside of the sample bottle.
5. Fill the bottles from an undisturbed part of the lake (i.e. not where someone has just walked through and stirred up the sediment).
6. Rinse out filtering apparatus with water from each site prior to collecting your filtered sample.
7. Label each bottle with the site name, the date, and the type of sample (i.e. TPU, TPF, MI, TM, TN, DOC/DIC) AS SOON AS YOU FINISH SAMPLING, or even prior to sampling.
8. Make sure the lid is on as tightly as possible.
9. When shipping supplies in a cooler, all bottles need to be protected by wrapping in newspaper and cardboard or other packing material placed between layers and bottles to keep bottles from breaking. Also include freezer packs to keep samples cool.
10. Before sending samples to NLET, fill in the NLET label with the appropriate schema code (these can change from year to year, so check with CCIW to confirm you have the right ones).
11. Upon return to the lab, the water samples for TPU and TPF (see below) need to be acidified with 1 ml of 30% H₂SO₄ per 100 ml of sample water (TRACE METAL GRADE ACID ONLY)

 Quick summary of sampling to be done in the field for each site:

            At the lake, fill the following bottles with unfiltered water:
                        1) Trace metals (TM), plastic 1 L Nalgene2) Major ions (MI), plastic 1 L Nalgene
                        3) Total phosphorus unfiltered (TPU), 125 ml rectangular glass
                        4) Two 1 L plastic Nalgene bottles for pH, conductivity, and filtering later on that day back at the camp.

 Back at the camp:
                         5) Measure pH
                        6) Measure conductivity
                        7) Filter water for total phosphorus filtered (TPF), total nutrients (TN), and DOC/DIC (all use the same Sartorius filter [we use AcetatePlus,            Supported, Plain, 0.45 micron, 47 mm, from Osmotics Inc. A04SP04700]; keep WATER)
                        8) Filter water for chlorophyll a (using GF/C 4.25 cm filter; keep FILTER)
                        9) Filter water for POC/PN (using GF/C 2.5 cm pre-ignited filter; keep FILTER) 

Summary of equipment & bottles needed:       
    a)      Several 1 L plastic Nalgene (need 2 per site per day, but will empty each day, so can re-use)
    b)      125 ml  round plastic Nalgene (2 per site: one for trace metal and one for major ions)
    c)      125 ml rectangular glass bottles (2 per site: one for total phosphorus unfiltered {TPU} and one for total phosphorus filtered {TPF})
    d)      125 ml round glass bottles (2 per site: one for total nutrients filtered {TN} and one for dissolved organic carbon / dissolved inorganic carbon {DOC/DIC})
    e)      Small plastic Petri dishes (2 per site: one for chlorophyll a and one for POC/PN)
    f)        Sartorius filters, d = 47 mm (need 1 to 2 for each site)
    g)      Whatman GF/C filters, d = 4.25 cm (need one per site, for CHL a)
    h)      Whatman GF/C filters, d = 2.5 cm (need one per site, for POC/PN, pre-ignited {see above})
    i)        pH meters, buffer solutions (PH = 4, 7 and 10), extra batteries
    j)        Conductivity meter, extra batteries
    k)      Filtering apparatus
                a.       vacuum flask
                b.      hand pump with tubing
                c.       filter base (two sizes for both sizes of filters)
                d.      filter cup (two sizes for both sizes of filters)
    l)        Masking tape
    m)    Electrical tape
    n)      Sharpies (water-proof marker)
    o)      Aluminium foil
    p)      Tweezers
    q)      NLET labels 

Specific procedures for each sample:

 1) Trace Metals (TM)
            - Use 125 ml round plastic Nalgene bottle
            - Fill with unfiltered lake water at lake

 2) Major Ions (MI)
            - Use 125 ml round plastic Nalgene bottles
            - Fill with unfiltered lake water at lake

 3) Total Phosphorus (TP): both unfiltered (TPU) and filtered (TPF) fractions
            a) 2 rectangular glass 125 ml bottles: one for TPU and one for TPF
            b) For TPU: fill with unfiltered lake water at lake, clearly label right away
            c) For TPF: fill with filtered water, use Sartorius filter (same as for total nutrients and DOC/DIC; best to use filtrate after doing TN and DOC/DIC), clearly label right away

 4) Chlorophyll a
            a) Keep the filter, not the water
            b) Use water from 1L Nalgene (mix well before using)
            c) Filter 300 ml of water, use GF/C filters (d = 4.25 cm); NOTE: can use smaller volume if necessary, but be sure to mark on label. [Note, we use 300 ml, but if there is more water, NLET would prefer 1 L to be filtered, but due to logistics, we filter a smaller volume]
            d) Do not exceed maximum pressure of 15 PSI on vacuum pump (so that cells do not break)
            e) Fold filter in half using tweezers and place in small Petri dish. Label directly on Petri dish the analysis to be done (i.e., CHL a), the site name, date, amount filtered.
            f) Wrap Petri dish in aluminum foil to keep out light and label it (as above) again. . . . . .
            g) Keep filter cool and in dark, frozen is best.

 5) POC/PN
            a) Keep the filter, not the water.
            b) Filter 150 water, use GF/C filters (d = 2.5 cm) that have been pre-ignited at 525˚C for 2 hours [as noted above, NLET would prefer more water filtered, but due to logistics, we typically filter 150 ml]
            c) If your filter clogs before reaching 150 ml, be sure to mark it on the label
            d) You don't need to fold filter; place in small Petri dish using tweezers, label (including the amount of water filtered), wrap in foil, and label again.
            e) Keep it cool, frozen is best.

 Note: Because the filtrate from chlorophyll and POC/PN filtrations is discarded, this filtered water can be used to rinse the filter flask with lake water from that sample prior to filtering for TN and DOC/DIC. Thus, it is preferable to filter for chlorophyll and POC/PN first. 

 6) Total Nutrients (TN)
            a) Filter enough of the rest of the water from the 1 L Nalgene bottle to fill two 125 ml bottles (2 X 125 ml = 250 ml, but do some extra in case of spills)
            b) Use Sartorius filters (d = 4.7 cm)
            c) Here you keep the filtered d water, not the filter
            d) Store in glass bottleses
            e) Keep cool and in the dark

 7) DOC/DIC
            a) Use filtered water as for total nutrients, but put it in its own glass bottle.
            b) Use Sartorius filters (d = 4.7 cm)
            c) Here you keep the filtered d water, not the filter
            d) Store in glass bottles
            e) Keep cool and in the dark

 WATER SAMPLE CONTAINER WASHING PROCEDURES

 (Updated June 2008) 

Method 1 Major Ions (Water): Round plastic bottles marked with yellow tape 

• Add 5 ml of 10% HCl per 125 ml  round plastic bottle
• Fill the bottle to the rim with distilled deionized water (DDW)
• Cap and soak for at least three days
• Rinse 4 times with DDW

Method 2 Total Phosphorus (Water): Square glass bottles

• Add 5 ml of 10% H₂SO₄ per 100 ml bottle
• Fill the bottle to the rim with DDW
• Cap and soak for at least three days
• Rinse 4 times with DDW

 Method 3 Nutrients (Water): Round glass bottles 

• Add 5 ml of 10% H₂SO₄ per 100 ml bottle
• Fill the bottle to the rim with DDW
• Cap and soak for at least three days
• Rinse 4 times with DDW

Method 4 Trace Metals (Water): Round plastic bottles marker with red tape

• Add 5 ml of 10% HNO, per 125 ml bottle
• Fill the bottle to the rim with DDW
• Cap and soak for at least three days
• Rinse 4 times with DDW

 Note:   Once at the lake you will rinse both the bottles and the lids at least three times with lake water as a final cleaning.