# Presentation: 211668

## Challenges of Conducting Analytical Chemistry in Environmental Matrices

- May 8th 2006
- Meg Sedlak and Don Yee
- San Francisco Estuary Institute
- Oakland, California

## Outline

- Overview of the Regional Monitoring Program for Water Quality (RMP)
- Challenges of environmental samples
- Ubiquitous contaminants, trace concentrations, complex matrices
- Specific examples – PAH and PBDEs
- Summary

## Regional Monitoring Program

**Regional Monitoring Program**

**Founded in 1993 **
** **
**Monitoring trends and distribution of pollutants**
**Estimating loads**
**Measuring exposure and effects**

## RMP Structure

**•  ****Funded by NPDES dischargers**

**•  ****Collaborative - Quarterly meetings with dischargers, **
**   ****regulators, & staff**

**•  ****Core element – Status and Trends**
**•  ****Pilot and special studies**

**RMP Structure**

## Status & Trends Annual Monitoring 

- Summer
- Water, sediment,  bivalves, & sportfish
- Analytes:
- Trace elements (Ag, As, Cd, Cu, Fe, Hg, MeHg, Mn, Ni, Pb, Se, Zn)
- Organics (PCBs, PBDEs, Pesticides, PAHs)
- Toxicity (sediment & water)
- 5 different laboratories

## Regulatory standards vs. Environmental concentrations

- Protecting analyst from sample

- Protecting sample from the analyst

## Sampling & Analysis Chain

- Extract

- Chemical Analysis

- “Clean”
- Containers

- Supplies &
- Equipment

- Laboratory
- Environment

- Reagents
- Glassware

- Field Crew

- Result

- Field blank

- Proof

- Lab blank

- Cleaning

- Field
- Environment

**Sampling & Analysis Chain**

## Sampling & Analysis Chain

- Extract

- Chemical Analysis

- “Clean”
- Containers

- Supplies &
- Equipment

- Laboratory
- Environment

- Reagents
- Glassware

- Field Crew

- Result

- Field blank

- Proof

- Lab blank

- Cleaning

- Field
- Environment

**Sampling & Analysis Chain**

**“****External” Sources of Contamination**

**“****Internal” Sources of Contamination**

## Water Organics- Collection

-   AXYS system
-  1 m below       surface
-   100 liters
-   Prefilter, glass filter (1 um pore size) and XAD resin
-   Extract split 5 ways

**Water Organics- Collection**

## Water - Organics

- Glass Filters and XAD resin
- Soxhlet extracted
- 12 hrs, closed loop distillation
- Silica gel cleanup
- Analysis by GC/MS for PAHs

## PAH Blanks 2002 vs. 2003

## Water Organics- What changed?

- Cleaning
- 2003 switched to acid-cleaning of glassware
- Change in solvent
- stabilizer in toluene (proprietary)
- PAH Formation
- Mechanism unknown
- Activation sites/heat?

**=Si-OH**

- ?

## Alternatives Considered 

**Alternatives Considered**

- Other solvents
- Acetonitrile/Dichloromethane- recovery problems w/ other analytes (pesticides)
- Splitting samples
- XAD possible
- Filters? No clean-sawing SOP developed

## Alternatives Considered (cont’d)

- Whole water samples – Pros and Cons
- Cons
- 5-fold increase in detection limits
- Would lose some PAHs (e.g., acenaphthene)
- A lot of water samples needed....
- 4 liters per analyte
- 31 sites => 620 L => 620 kgs
- ...meaning a whole lot of weight.

## Alternatives – Whole Water

**Cons:**
- Liquid-liquid extraction
- Time-consuming to extract 4 liter samples

**Pros:**
- Weight training

## Alternative Chosen

- Ambient Temperature eXtraction (ATX)
- Developed by AXYS Analytical
- Filters sonicated in acetonitrile and hexane
- Good recovery for all analytes

## 2003 vs. 2005 PAH Blanks

## 2005 Total PAH Concentrations in Water

**2005 Total PAH Concentrations in Water**

## PBDEsEmerging Contaminant

- Wide-spread use
- Increase scrutiny
- Health effects
- Phase out in EU & CA
- Deca highest use

- Source: Stapleton et al.,  2005.  ES&T 39(4); Wilford et al., 2005 ES&T 39(18); and
- BSAF.

## PBDEsAn Emerging Challenge

- Blank contamination in lab environment?
- Present in plastics, soft furnishing, electronic equipment

## PBDEs: A spec of dust is important no matter how small ....

- 	 Source:  Stapleton *et. al*, ES&T 39 (4)

## Similar challenges with other Emerging Contaminants

- Ubiquitous, trace levels, complex matrices
- Perfluorinated Compounds
- Teflon liners, tubing, septa, textiles
- Phthalates
- Gloves and septa

## Summary

- Large-scale environmental monitoring programs require adaptive management
- Off-the-shelf methods may not work
- Modification of methods
- Working with laboratories to solve the problem
- Many sources of contamination
- Internal contamination (function of the method)
- External contamination (introduced as a result of lab environment, supplies, equipment, staff, etc.)
- Need strong QA/QC
- New analytes = new sources and challenges

## Acknowledgements

- Brian Fowler and Dale Hoover
- (www.AXYStechnologies.com)

- Francois Rodigari and Saskia van Bergen
- (www.EBMUD.com)

## Questions?

- All of RMP data and reports are available on-line at www.sfei.org