Mercury in the Environment and Water Supply

 

Links

 

Mercury Analysis (Univ. of Alberta)

 

 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 

 

 

 

 

 

 

 

 

Mercury Sampling:
Methodology used by Martin Shafer of the Water Chemistry Program at University of Wisconsin-Madison

 

image from http://wi.water.usgs.gov/pubs/FS-216-95/

 

 

 

 

Clean Suits and Gloves Must Be Worn For All The Following Steps.

Lowering Tubing Line

Open plastic cartons containing sampling line and kevlar support rope. Tie kevlar rope to loop of Teflon string attached to sampling-line weight. (The end of the rope is two feet above sampling intake). Slowly and carefully begin removing lower end of sampling line (i.e.
Teflon weight end) from plastic bag (use extreme caution to avoid kinking and contamination), insert weight through receptacle on end of boom and lower into river to first depth (0.2 x River Depth). Secure kevlar support rope onto starboard plastic cleat. Keep remainder of sampling line tubing in plastic bag until pump head tubing is attached.

Note: Rope is marked in one foot increments - beginning six inches from the end. Use the six inches to tie off to Teflon string. The distance from sampling ports to top of Teflon string is two feet. A double line is marked every five feet, and a triple line is marked every 10 feet. To drop the sampling line to the lower depth, the kevlar rope is un-cleated, and both rope and Teflon sampling line slowly let out to (0.8 x River Depth). It is usually necessary to uncouple Sampling Line from pump-head tubing before lowering line. Clean-hands uncouples and re-couples sampling line from pump-head tubing.

Geo-Pump Loading and Sample Line Connection

Load pump-head tubing into Geo-Pump using clean protocol. {Gloved dirty hands opens pump head clamp lever and holds outer bag of pump-head tubing, while gloved clean hands removes inner bag and loop of tubing. Clean hands inserts closed tubing loop into pump head and dirty hands closes clamp lever making sure that tubing is properly positioned. Dirty hands makes sure that Teflon Tubing Adaptor Fitting (TTAF) and plexiglass clamp ring (PCR) are ready. At this point dirty hands re-gloves, and retrieves open end of sampling line from storage bag, while clean hands opens pump head tubing loop. Dirty hands gives clean hands sampling line who inserts it into pump head tubing. Dirty hands collects TTAF bag and opens outer bag, while clean hands opens inner bag and removes TTAF and tightly inserts it into the long end of the pump head tubing. The TTAF bags should be kept in the sample transport cooler during sampling (inner bag is always kept inside dirty outer bag. Dirty hands, with new gloves, collects PCR from storage bag, removes PCR, and holds it while clean hands inserts TTAF into PCR. Dirty hands then inserts assembly into groove in sampling platform. The PCR bag should also be kept in the cooler during sampling to minimize contamination and prevent it from being blown away.

Sample Collection

Place the appropriate sample bottles into the plastic sample organizing container using the following protocol. The outer bags should have been previously labeled with site and sample type information. The outer bags are removed using clean techniques and sample bottles with inner bag are placed in the organizing container. Dirty hands (with new gloves) retrieves appropriate double bagged Teflon sample bottle and opens outer bag. Clean hands (with new gloves) pulls inner-bag out of outer bag and places single-bagged bottles in the organizing container. Outer bags are stowed in the sample transport cooler, out of the wind.

The typical sampling sequence will be:
[1] 250 mL Unfiltered sample for Trace Metals
[2] 500 mL Unfiltered sample for Mercury
[3] 125 mL Unfiltered sample for Methyl Mercury (see Note)
[4] 1000 mL Unfiltered sample for SPM and DOC
[5] 250 mL Filtered sample for Trace Metals
[6] 500 mL Filtered sample for Mercury
[7] 125 mL Filtered sample for Methyl Mercury (see Note)
Filling each bottle ½ full.

Note: For Methyl Mercury; Sheboygan, Manistique, Pere Marquette, and Grand rivers only.
This sequence will be repeated at the lower depth (except that filtered samples will be collected first) to fill the remaining ½ of bottle and then samples are acidified, and double-bagged.

 

Upper Depth

Unfiltered Sample Collection

Dirty hands starts Geo-pump and adjusts to moderately high speed to flush lines (Verify that water flow is correct, through platform hole, and not splashing sides). Sampling lines are flushed for a minimum of five minutes before unfiltered samples are collected.

Sample Bottle Handling: Clean hands (with new gloves) pulls appropriate bottle out of inner-bag leaving inner-bag in organizing container.

Trace Metal Sample Collection: Teflon bottles are supplied empty and dry. Clean hands reaches under water stream and partially (c) fills bottle. The bottle is loosely capped and gently shaken to rinse. This process is repeated for a total of three bottle rinses. On the fourth collection the bottle is filled ½ full. Do Not Touch Bottle Mouth To TTAF Or Any Other Surface. Clean hands then returns sample bottle to inner-bag in organizing container. The bags do not have to be sealed at this point. Dirty hands removes and replaces organizing container lid during sampling.

Mercury Sample Collection: Teflon bottles are supplied filled with dilute HCl. Clean hands dumps acid into waste container. Do Not Touch Bottle Mouth To Waste Container Or Any Other Surface. Clean hands reaches under water stream and partially (c) fills bottle. The bottle is loosely capped and gently shaken to rinse. This process is repeated for a total of four bottle rinses. On the fifth collection the bottle is filled ½ full. Clean hands then returns sample bottle to innerbag in organizing container. The bags do not have to be sealed at this point. SPM - Carbon

Sample Collection: One-Liter polyethylene bottles are supplied empty and dry. Clean hands reaches under water stream and partially fills bottle. The bottle is loosely capped and gently shaken to rinse. This process is repeated for a total of three bottle rinses. On the fourth collection the bottle is filled ½ full. Clean hands re-gloves after handling the poly bottle.

 

Filtered Sample Collection

After all unfiltered samples are obtained from the upper depth, dirty hands reduces pump speed and then shuts off pump. Dirty hands re-gloves, retrieves a bagged Calex filter, and opens outer bag. Clean hands opens inner bag, removes filter capsule, opens vents, and drains off storage MQ into river (The filter bags may be discarded - the filter capsule is a disposable, single-site use, item). Dirty hands removes PCL/TTAF assembly from sampling platform, and clean hands uncouples TTAF and screws filter capsule onto TTAF. Clean hands inserts filter capsule into support on sampling platform. Dirty hands starts Geo-pump and adjusts to moderate speed to flush capsule (Verify that water flow is correct, through platform hole, and not splashing sides). The filter capsule is flushed for five minutes or approx. 3 L before filtered samples are collected. At this point Filtered Trace Metal samples and Filtered Mercury samples are collected in an identical manner to unfiltered samples as described above. To minimize the potential for filter clogging, dirty hands shuts off pump after each rinse or sample has been obtained. Upon completion of Filtered sample collection from the upper depth, cleanhands un-couples Teflon sampling line from pump-head tubing and dirty hands lowers tubing to 0.8 depth. When at depth, the sample tubing line is then reattached to the pump-head tubing using the clean technique.

 

Lower Depth

The collection process is identical to that described above for Upper Depth, except that obviously ½ full bottles are not rinsed and filtered samples are collected first. The protocol for flushing and equilibration of sampling line and filter is similar to Upper Depth, except that here one is flushing the line and filter as a unit. Flushing as a unit for five minutes should not present a problem except under conditions of very high suspended solids levels. If during Upper Depth sampling or early stages of Lower Depth flushing, significant reduction of sample flow rate through the filter is noted, do the following to minimize filter clogging. Uncouple filter capsule from the TTAF and flush the sample tubing line for the full five minutes. While tubing is flushing, drain the river water from the capsule filter. After tubing is flushed, connect to drained filter and flush filter for 90 seconds. Clean techniques must be followed. Bottles are filled to near capacity, leaving space for preservation acid. After each sample bottle is filled, and before rebagging, preservation acid is added to the sample.

 

image from http://wi.water.usgs.gov/pubs/FS-216-95/

 

 

 

Acidification

Trace Metal Sample Acidification (250 mL Sample Bottles)

Acid (50% Ultrex HNO3) is supplied pre-measured in small Teflon Vials, one for each sample. Acid transfer to the sample must be quantitative. Dirty hands (with new gloves) retrieves the bag containing acid vials and opens it. Clean hands reaches in and removes a vial. Dirty hands wrenches open the vial while clean hands holds it. Clean hands then removes vial cap and pours acid into sample bottle which should be available and loosely capped on work surface. Used acid vials are re-capped and placed into a designated Zip-bag, to be returned to Water Chemistry Lab along with metal samples. Note the acid batch number on the field data sheet. The acidified sample is ready to be double-bagged using clean-hands protocol after the cap is wrenched tight. Clean hands holds bottle tightly while dirty-hands takes a double-bagged channel-lock pliers to cap. Clean-hands twists bottle to secure cap. Place new bags on the wrench before use at each site, and during a sampling period if the bags appear worn.

Mercury Sample Acidification (500 mL Sample Bottles)

Acid (50% HCl) is supplied in a 250 mL double-bagged Teflon bottle. Also supplied is a Teflon measuring vial into which acid is poured to measure out 10 mL aliquots. Before starting the acidification process, verify that the samples to be acidified are organized on the clean work surface, and that their bottle caps are loose. Dirty-hands retrieves acid bottle and opens outer bag.
Clean hands opens inner bag and removes Teflon acid bottle, setting it on plastic covered work surface. Dirty-hands retrieves Teflon measuring vial and opens outer bag. Clean hands opens inner bag and removes vial. Temporarily place acid and vial bags (inner bag inside outer bag) in the sample organization box. Clean hands pours acid into the vial up to the etched line and then quickly pours contained volume into the sample bottle. Do not let acid measuring vial touch lip of sample bottle. Clean-hands - dirty-hands procedures are then used to wrench shut and double-bag sample bottles, and to double bag acid bottle and measuring vial.


As Part of:Shafer, Martin. Trace Metal and Mercury Sampling. Methods for Lake Michigan Tributaries. 2(1): 1-231.( www.epa.gov/glnpo/lmmb/methods/lmtfpro.pdf )