Inland Reef / Reefs.org Salt Analysis Project

[MattM]

John -

There are some issues with remote collection. We would have no control over the specific sampling location, but more importantly, the sample would have to be appropriately filtered at the point of collection so that death and decay of plankton does not ruin the sample in shipping.

I'm sure these things could be addressed, but we have to question if it is worth it for a control sample that we are not necassarily going to include in the final results.

 

[JohnL]

There are some issues with remote collection.

Thanks Matt. That makes sense.

 

[StevenPro]

I don't know about you, but I mix my saltwater in buckets or a garbage can. Not a specially prepared Teflon container. I understand the wish to have the highest accuracy, but this is still a study to be used by hobbyists. If these plastics have some sort of negative consequence, why not measure that, too. As I understand the study, it is to see if artificial salt mixes are toxic (hence the bioassay) compared to natural sea water and if so why (the reason for the analysis). To me, mixing and storing the water as per typical conditions seems much easier and more relevant.

 

[randy holmes-farley]

I agree, I mix mine in a trash can too. That's certainly something to consider measuring, but not something that you'd want to hold against a salt mix. Additionally, you'd need a "standard" trash can, as there is no reason to believe all types to be the same. Consequently, if you're looking into that aspect, the number of samples might start to balloon, along with costs.

 

[JohnL]

Could everyone interested please vote in this poll about which salt mix people currently use.

 

[liquid]

Way ahead of you John. We've had this up for about 1-2 months now and recently I edited the survey to include the salts that Inland wanted to test.

http://reefs.org/GBSurvey/

Shane

 

[oceanarus]

As the person that originally suggested using General Engineering Laboratories, I would like it if anyone has any questions on the capabilities of the lab please visit www.gel.com . This lab is very capable of analyzing any matrix desired. As for QC samples, all Matt needs to do is talk to the project manager at the lab and express his desire that QC samples be run. It is standard operating procedure here to run a matrix blank, duplicate, matrix spike, and a laboratory control sample (a blank spiked with a NIST certified analyte) with every batch of samples that are analyzed. And as for sample bottles, for metals analysis Nalgene bottles (from Daniels Scientific Inc.) are the ones used by various environmental regulatory bodies and can be supplied by the laboratory upon request. I think someone else already shot it down, but using teflon is utterly absurd (the price would be astronomical). I have seen more samples come into this lab than anyone can imagine, and have never once seen anyone use a teflon sample container.
I should point out that I am not a designated representative of General Engineering Laboratories, but I do work here (radiochemist) and have some knowledge of the ICP-MS / metals prep / sample hadling-recieving process. And also happen to be a reefer that would like to see this study happen.

 

[JohnL]

Way ahead of you John. We've had this up for about 1-2 months now and recently I edited the survey to include the salts that Inland wanted to test.

Shane, I can't find Marine Enterprises Crystal Sea. Is it there?

 

[liquid]

Shane, I can't find Marine Enterprises Crystal Sea. Is it there?

Crystal Sea / Forty Fathoms (unless I'm mistaken). 9 down from the top.

Shane

 

[JohnL]

Shane, I can't find Marine Enterprises Crystal Sea. Is it there?

Crystal Sea / Forty Fathoms (unless I'm mistaken). 9 down from the top.

Shane

What's Forty Fathoms ?

 

[kazzoo]

I think someone else already shot it down, but using teflon is utterly absurd (the price would be astronomical). I have seen more samples come into this lab than anyone can imagine, and have never once seen anyone use a teflon sample container.
.

Use of teflon is important if any organics analysis will be done. As someone who has done much organics analysis, and seen the chromatographic runs of samples that have come into contact with "plastic" during the collection, extraction, and clean-up phases of sample preparation, I believe it is quite important to have that type of container. I agree it is unneccessary if only metals analysis will be done.

BTW, how long have you been with GEL? I was a post-doc with NOAA down at Ft. Johnson, and know they have from time to time sent samples to GEL for metals analysis.

 

[liquid]

What's Forty Fathoms ?

Crystal Sea®/Forty Fathoms® Marinemix
manufactured by Marine Enterprises International

http://www.aquacraft.net/w0008.html

Shane

 

[randy holmes-farley]

oceanarus:

I think someone else already shot it down, but using teflon is utterly absurd (the price would be astronomical). I have seen more samples come into this lab than anyone can imagine, and have never once seen anyone use a teflon sample container.
.

Have you ever seen anyone accurately quantify NSW levels of copper from a collected sample using anything selse?

You may consider yourself smarter than the chemical oceanographers that finally solved this very long standing problem using teflon sample bottles. I don't have the same confidence in myself. I don't consider myself more knowledgeable in this field than the chemists the reported the first successful results, so I reported how they succeeded. If you don't care to follow the advice, feel free to use whatever you see fit. You may even be correct, I don't know.

FWIW, the price of teflon bottles is not "astronomical". I use them all of the time. From Cole Parmer you can buy 60 mL Teflon bottles for $21.60 each and they are claimed to be "The most inert bottles available......Use them for....trace metal analysis..."

FWIW, these are Nalgene bottles. When you say Nalgene bottles are OK, maybe they really are Teflon. Actually, I expect you folks do use something else (like HDPE), I'm just pointing out that "Nalgene" is a brand, not a material.

 

[oceanarus]

Use of teflon is important if any organics analysis will be done.

BTW, how long have you been with GEL? I was a post-doc with NOAA down at Ft. Johnson, and know they have from time to time sent samples to GEL for metals analysis.

If you want organic analysis done, send a separate sample in a glass container.

Been with GEL for 4 years, but as I said b4, I am a radiochemist, so I don't get involved much with metals analysis. Except for the prep work on some of the high-rad samples.

 

[JohnL]

What's Forty Fathoms ?

Crystal Sea®/Forty Fathoms® Marinemix
manufactured by Marine Enterprises International

http://www.aquacraft.net/w0008.html

Shane

Thanks Shane. No mention of Forty Fathoms on the manufacturer's web site here http://www.meisalt.com/Site/Products/crystal.htm

I can go vote now

 

[Habib (Salifert)]

John:

What's Forty Fathoms ?

This is the old name and perhaps also an old formulation of Marine Enterprise's Crystal Sea Marinemix.

If I am correct then they made the change about 2 years ago.

 

[randy holmes-farley]

Here are a couple of references showing that oceanographers do use teflon bottles and loads of other extreme precautions that may seem unnecessary toi folks uninvoled in such studies:


Sampling and analytical methods for the determination of trace metals in surface seawater. Nolting, R. F.; de Jong, J. T. M. Netherlands Inst. Sea Res., Den Burg Texel, Neth. International Journal of Environmental Analytical Chemistry (1994), 57(3), 189-96.
Abstract

Recently implemented techniques and sample strategies to det. trace metals in seawater are discussed. Only with the highest precautions to prevent contamination, can reliable results be obtained, starting with prepn. of sample bottles and equipment in the lab. A rubber boat, Go-Flo samplers, and a specially designed teflon-coated winch with Kevlar rope is used to collect samples. At sea, prevention of sample contamination is highest priority. This implicates using a clean air van or at least a laminary flow bench. Acids must be sub-boiling distd. in a quartz still and stored in teflon bottles. Sample preconcn. on board or in the home lab. must be done in clean rooms. Current procedures used to sample and analyze seawater for trace metals are discussed.


Mercos - a simple teflon sampler for ultratrace metal analysis in seawater. Freimann, Peter; Schmidt, Diether; Schomaker, Karl. Lab. Suelldorf, Deutsch. Hydrogr. Inst., Hamburg, Fed. Rep. Ger. Marine Chemistry (1983), 14(1), 43-8.

Abstract

A simple sampling technique for ultratrace element anal. of coastal and surface seawaters (max. depth 100 m) is based on interchangeable 500-mL Teflon bottles which are used as both sampling and storage vessels. The seawater samples are stabilized in situ by preacidifying the sampling bottles.

 

[randy holmes-farley]

This reference shows that both teflon and polyethylene bottles needed to be acid washed un an ultrasound bath prior to use to be suitable for trace metals analysis of seawater. The point is, this is not your usual metals analysis problem.

Ultrasonic bath in container preparation for storage of seawater samples in trace metal analysis. Kinsella, Brian; Willix, Rodney L. Sch. Appl. Chem., West. Aust. Inst. Technol., Bentley, Australia. Analytical Chemistry (1982), 54(14), 2614-16

Abstract

New polyethylene [9002-88-4] and Teflon [9002-84-0] containers that had been acid washed by standing with 1:1 HNO3 and HCl for 14 days still contained detectable amts. of Cd, Pb, and Cu. These could be removed relatively easily by acid washing in an ultrasound bath. On adopting an ultrasonic acid washing procedure, measured values for Cd, Pb, and Cu in seawater decreased significantly, and better precision was achieved. Containers so treated showed little evidence for adsorbing these metals from seawater samples. The use of an ultrasound bath is an effective method for prepg. sample containers and reduces the prepn. time.

 

[oceanarus]

You may consider yourself smarter than the chemical oceanographers that finally solved this very long standing problem using teflon sample bottles.

I'm just pointing out that "Nalgene" is a brand, not a material.

Never considered myself smarter than anyone else. I was simply speaking from experience of being on the recieving end of people that take all the precautions you have mentioned during their sampling, and never once have seen a teflon bottle used.

Good point about the Nalgene, I should have been more specific. They are HDPE bottles "cleaned to the recommended EPA wash procedure as set forth in EPA's 'Specifications and Guidance for Obtaining Contaminant-Free Sample Containers', and this lot was tested and found to comply with or be lower than the EPA specifications" (quoted from the Certificate of Analysis that is included in every box of their containers)

 

[randy holmes-farley]

The EPA guidelines are of zero use in understanding seawater samples. The EPA is concerned with copper levels of 1.3 ppm or higher in drinking water:

http://www.state.me.us/dhs/eng/water/Le ... 20Rule.htm

We are concerned with ppb levels or lower (at least in real NSW).

I quite agree that polyethylene bottles are suitable for ppm levels.