A s pec ts of E nvironmental A ir Monitoring and A nalys is

G avin P arcs i

UNSW Water Research Centre, Atmospheric Emissions and Odour Laboratory

A tmos pheric E mis s ions & Odour L aboratory C urrent R es earc h P rojec ts

• Characterising Sewer Gas Composition • Assessing Efficiency of Odour Abatement Techniques • Characterising the VOC/VONC/VOSC/Odorants from biosolid

sludge through treatment process • Fate & Transformation of VOSC (developing understanding of

sulphur compounds in different environments) • Investigating odour and VOC generation in poultry houses • Indoor Air Quality Assessment • Investigating nuisance odour complaints

• US EPA TO Series Methods • TO-14/15 Canisters

• TO-1/2/17 Sorbent Tubes

• Wide application to the analysis of Air Toxics

• Principally BTEX and halo-hydrocarbons

• Limited applicability to odorant assessment

• No sulphur or nitrogen compounds

Haloc arbon 114 1,2-Dic hloroethane 1,3,5-T rimethylbenzene Methyl Ac etate Haloc arbon 11 T ric hloroethene 1,2,4-T rimethylbenzene Methyl tert-B utyl E ther Haloc arbon 113 1,2-Dic hloropropane Dic hlorobenzenes Methyl E thyl K etone 1,1-Dic hloroethene c is -1,3-Dic hloropropene 1,2,4-T ric hlorobenzene E thyl Ac rylate Methylene C hloride T oluene Hexac hloro-1,3,-butadiene 1,1 Dic hloroethane T rans -1,3-Dichloropropene Methyl Is obutyl K etone

T etrachloroethene C hloroform 1,2-Dibromoethane Acetone C hlorobenzene 1,1,1-T richloroethane E thylbenzene 2-P ropanol m-Xylene C arbon tetrachloride p-Xylene Acrylonitrile o-Xylene B enzene 1,1,2,2-T etrachloroethane Is oprene F urfural Acetonitrile 1,3-butadiene c is -1,2-dichloroethene Methyl Acrylate

C urrent G eneric (V OC ) A pproac h

E nvironmental A ir S ampling

Sorbent tubes provide compact and robust sampling for large volumes. Logistically advantageous.

“Bag” sampling allows the whole matrix to be collected without the selectivity of a sorbent; however, they are large and bulky.

Need for F lexibility, C us tomis ation and S ens itivity

• Environmental analysis is multifaceted environmental odour assessment (dilution olfactometry) indoor air quality assessment (VOC and GHG) identification and elucidation of environmental odours (VOC and non-

VOCs)

• US-EPA methodology “standard” can be too rigid and constrained to identify the cause of issues

• Essential to identify the nuisance as opposed to the regulated criteria

• IMPORTANT: chosen method must maintain (or improve) robustness, reliability, and MDL’s

GC-MS analysis of sorbent tubes (TO-17)

S tandard A pproac h - C hemic al S pec iation

S orbent T ube and Heads pac e C omparis on

G C -Olfac tometry? • Odorants ∉ VOCs • C aveat: Subjectivity

• Aldehydes, ketones, carboxylic acids • Different characteristics, different odour thresholds

V OC Odorants

Chemical Character OTV (mg/m3) 3-methyl-butanal Rancid, malt 0.002 2,3-butanedione Rancid butter 0.0035

Toluene Sweet, solvent 25 Cylcohexanone Sweet, peppermint 0.048 Butanoic Acid Vomit 0.001

3-hydroxy-2-butanone Malty 3

Potential for transformation in the environment and during analysis Olfactory stimulation can provide a warning of danger

R es earc h A reas of the UNS W A E & O L aboratory R outine A nalys is Ins trumentation

• Initially (mid 2005) single GC which combined Mass Spectrometry with Olfactory detection to identify odorants within odorous matrices (Agilent 6890N:5973N GC-MSD w/ Gerstel ODP2 )

• Continuous expansion (2007-present) duplication of GC-MSD/ODP (7890A:5975C GC-MSD,

with additional FPD for reduced sulphurs (DMS, DMDS, DMTS)) Trace level (pg) gas phase Sulphur and Nitrogen

determination (7890A:255NCD+355SCD) Additional GC-SCD system for stability study of volatile

organo-sulphur species (7890A:355SCD)

UNS W WR C A E & O Markes E quipment

• Thermal desorption methodologies provide reliable and reproducible results for different environmental sampling (humid, dry, high/low concentration, remote sampling)

• Each GC has a Markes front end (QTOF pending)

• Each Instruments has dedicated Markes front inlet VOC & Odorant analysis - (Ultra/U-Inlet)-TD-GC-MSD/ODP

• U-Inlet provides direct headspace sampling of samples VOC&VOSC analysis - UltrA-TD-GC-MSD/FPD/ODP VOSC analysis - CIA8-TD-GC-SCD (samples climate controlled) VOSC & VONC analysis - CIA Adv-TD-GC-SCD/NCD LL & Complex Matrix analysis - CIA Adv-TD-GC-QTOF (pending)

T D-G C -MS D/ODP (6890N-5973N) (T he Original Workhors e)

for VOC quantification and odorant speciation and prioritisation use sorbent tubes (w/UltrA) or direct headspace (U-Inlet)

MSD GC TD UltrA

ODP

G C -MS D/F P D/ODP (7890A -5975C )

for VOC quantification and odorant speciation and prioritisation, additional reduced sulphurs use sorbent tubes (w/UltrA) or direct headspace (U-Inlet)

TD UltrA MSD GC

FPD

ODP

E xample: Indoor A ir A nalys is (V OC and Odorants )

Nuisance odour complaint, required 25 l sample to identify compounds responsible

TIC: Complex VOC matrix

OSC: Few compounds responsible for nuisance

S ulphur Odorants

• Potent and objectionable odours • Highly volatile, may degrade during analysis and in

the environment • Not catered to with generic VOC methodologies

(US EPA TO-17 et alii) • Abatement processes focus on H2S (rotten egg

gas) • Design of processes need to accommodate a

larger variety of sulphur species • Mercaptans, sulphides, disulphides, trisulphides

etcetera

S ulphur Odorants

• Alliaceous character (P ungent!) • Low detection thresholds

Chemical Character OTV (mg/m3)

Hydrogen Sulphide (H2S) Rotten egg 0.002

Dimethyl Sulphide (DMS) Sulphury onion 0.049

Methyl Mercaptan (MeSH) Decomposing cabbage 0.0013

Dimethyl Disulphide (DMDS) Sulphurous vegetable 0.82

Ethyl Mercaptan (EtSH) Sulphurous fruity 0.0008

Diethyl Disulphide (DEDS) Gassy ripe onion 0.09 Ethyl Methyl Disulphide

(EMDS) Sulphurous truffle 0.062

Dimethyl Trisulphide (DMTS) Sulphurous cooked onion 0.014

MS D v S C D/NC D/F P D

• Mass spectrometry; affords flexibility, limitation of detection of highly volatile species

• SCD/NCD/FPD allows lower levels of detection and specific detection of targeted groups (esp. non-VOC odorants)

G C -S C D (7890A -355)

for organo-sulphur quantification use “odour” bags (Tedlar, Nalophthan etc) or Canisters

CIA8 TD GC SCD

S ulphur Odorants : limitations of analys is

• Fate and transformation of chemicals during • Sampling & Analysis • Sample storage • Through abatement systems • Between source and receptor (insert figure) • Change in odour characteristic • Targeted abatement and mitigation strategies • Different bag materials may impact on results • Methodological/Instrumentation influences (thermal

degradation)

F ate of V OS C s

Ethyl Methyl Disulfide

Diethyl Disulfide

Ethyl Mercaptan

Oxidation of Merc aptans

• Mercaptan readily oxidise to disulfides • 2RSH ⇌ RSSR • Equilibrium reaction favours disulphide formation e.g. (1) Ethyl Mercaptan

• Chemical: 2EtSH ⇌ DEDS • OTV: 0.0008 ⇌ 0.09 • Character: Sulphurous, Fruity ⇌ Gassy ripe onion

e.g. (2) Methyl Mercaptan • Chemical: 2MeSH ⇌ DMDS • OTV: 0.0013 ⇌ 0.82 • Character: Rotting cabbage ⇌ Sulphurous vegetable

Nitrogen Odorants

• Fishy, faecal, putrid character (P ungent!) • Low detection thresholds

Chemical Character OTV (mg/m3)

Ammonia (NH3) Characteristic, pungent 1.5

Trimethylamine (TMA) Pungent raw fish 0.00026

Indole Faecal 0.00006

Skatole Sewery 0.00035

Pyridine Putrid, dead animal 0.32

Putrescine Putrid, dead animal 0.0009

Cadaverine Putrid, dead animal unknown

C IA -A DV .-T D-G C -S C D/NC D (7890A -355/255)

for organo-sulphur/nitrogen quantification use “odour” bags (Tedlar, Nalophthan etc) or Canisters

C hanging Odour C harac ter with C onc entration

• Many chemical compounds elicit different chemosensory responses at differing concentrations 2,3-butanedione: sweet buttery (L); rancid fat (H) Skatole: floral perfume (L); nauseating faecal (H)

• Therefore an accurate quantification is needed to evaluate the impact specific odourants will have on a receptor

• Requires robust and reliable methods

FTIR Spectrometer (Agilent 660 FTIR w/ 1~16m

heated sample cell) for low level GHG determination) LTM-GC-MSD - 5975T (transportable GC-MSD for

field sampling and analysis: coupled with Markes Int’l. Air Server) GC-QTOF (Agilent 7200 accurate mass MSD)

R es earc h A reas of the UNS W A E & O L aboratory A dditional A nalys is Ins trumentation

F T IR (660 - for G reenhous e G as Monitoring)

for greenhouse gas determination use “odour” bags to collect sample

1~16m Variable path length cell

FTIR

“ A irS erver: T rans portable” (L T MG C -5975T )

for field based measurements (VOC quantification) use “odour” bags (Tedlar, Nalophthan etc) or Canisters

G C -QT OF (7890A -7200)

MSD GC TD

for trace analysis and complex matrix VOC quantification accurate mass for unknown analysis

T hank you for your attention