Spas Kolev.pdf

The potential of paper-based microfluidicdevices and passive samplers in chemicaldevices and passive samplers in chemical

oceanographic monitoring

Spas D Kolev

School of Chemistry, Center for Aquatic Pollution Identification and Management (CAPIM)

Th U i it f M lbThe University of Melbourne, Victoria 3010, Australia

Passive samplers

Deployed over extended periods of time (e.g. days, weeks) to provide

time-weighted average concentrations of the target chemical species

Low cost (no moving parts or power source) Low cost (no moving parts or power source)

Provide preconcentartion of the target chemical species

Allow the determination of labile species which are potentially

bioavailable

Small and mechanically strong (e.g. deployable in difficult to access or

‘hostile’ environments)

No special training is required for their handling

Passive samplers applied to marine systems

Polar Organic Chemical Integrative Samplers (POCISs)

Chemcatcher3M EmporeTM

disksdisks

Applications: Pharmaceuticals, pesticides (LOD – 0.01 – 1.5 M/L)Alkylphenols PAHs

Applications: Hg(II) (LOD – 1.7 ng/L)Organotin (LOD – 3 ng/L)P ti id

Alkylphenols, PAHs

S Seethapathy, T Gorecki, X Li, J. Chromatogr. A 1184 (2008) 234.

Pesticides

Passive samplers

Diffusion Gradient in Membrane Stripsus o G ad eThin-film (DGT) sampler Applications:

DDT, PCB (polyethylene)Pesticides (ethylene – vinyl acetate)Dioxines, furans, PCB (polyoxomethylene)

Binding layerDiffusive gel layerFilter membrane

Dioxines, furans, PCB (polyoxomethylene)

Outer sleeve

Base

Semi-Permeable Membrane Devices (SPMDs)

Applications: phosphate

Applications: Al(III)

Ferrihydrite

Applications: phosphate

Porous membrane

Ferrihydrite

Polymer Inclusion Membranes (PIMs)Composition: Base polymer (e.g. PVC, cellulose triacetate)

Extractant/Carrier (e.g. Aliquat 336, di(2-ethylhexyl)phosphoric acid (D2EHPA))

Plasticizer/modifier (e.g. 2-nitrophenyl octyl ether, dioctylphtalate, n-decanol)

Physical characteristics Homogeneouso oge eous Transparent Flexible and mechanically strong

Advantages: Longer lifetime than supported liquid membranes due to the reduced loss of the membrane liquid phase.

LD Nghiem, P Mornane, ID Potter, JM Perera, RW Cattrall, SD Kolev, J. Membr. Sci., 281 (2006) 7.M O’Rourke, RW Cattrall, SD Kolev, I.D.Potter, Solvent Extr.Res.Development, Japan 16 (2009) 1.MIGS Almeida, RW Cattrall, SD Kolev, J. Membr. Sci. 415-416 (2012) 9.

Preparation of the Zinc(II)-selective PIM

PIM composition:

PVC D2EHPA +PVC

glass ring

in THFD2EHPA (di-2-ethylhexyl phosphoric acid)

flat glass plate

OPO OO g p

SD Koleva, Y Baba, RW Cattrall, T Tasaki, N Pereira, JM Perera, GW Stevens, Talanta 78 (2009) 795.LL Zhang, RW Cattrall, SD Kolev, Talanta 84 (2011) 1278.LL Zhang, RW Cattrall, SD Kolev, Talanta 97(2012) 382.

PIM-based Zinc(II) passive sampler

Source phase: Zn(II)s + 3/2(HR)2 m ZnR2.HR m + 2H+s

Receiving phase: ZnR2.HR m + 2H+r Zn(II)r + 3/2(HR)2 m

S b i t f t i i d b hSubscripts s, r, m refer to source, receiving and membrane phases.

Paper-based microfluidic devices

Main characteristics

Liquids are transported by capillary force along hydrophilic (penetration) channels.

Optical detection is based on visual assessment of the colourintensity (colour charts) or colour intensity measurements.

Main advantages

Low cost

Portable

Disposable

Flexible in terms of design and the analytical reaction usedg y

Easy to use

Determination of orthophosphate

H2SO4Ammonium molybdateP t i ti t t tAscorbic acid Potassium antimony tartrate

Sample (10 L)

BM Jayawardane, ID McKelvie, SD.Kolev, Talanta 100 (2012) 454.

Optimization and calibration of the CardParameter Range studied Optimal value

Sulphuric acid concentration [M] 5.0 – 8.0 6.6

Volume of the molybdate/antimony (Mo/Sb) reagent [L] 0.25 - 1.5 0.5

Volume of the ascorbic acid reagent (75 mM) [L] 0.5 – 2.5 1.5

Molybdate concentration in the Mo/Sb reagent[mM] 42 - 210 126

Antimony(III) concentration in the Mo/Sb reagent[mM] 6 - 42 6

Reaction time [min] 5 - 90 10

Analytical figures of merit

Linear concentration range 2 (mg L-1 P) 0.2 – 10

Detection limit (mg L-1) 0.05

RSD (%) at 5 mg L-1 P 1.6RSD (%) at 5 mg L P 1.6

Stability ambient temperaturefreezer

15 days122 days

BM Jayawardane, ID McKelvie, SD.Kolev, Talanta 100 (2012) 454.

Interference studies

P standard Added Si P found

Si interference

[mg L-1 P] [mg L-1 Si] [mg L-1 P]1.0 0 0.98 (0.08)

1.0 1.0 0.98 (0.09)1.0 1.0 0.98 (0.09)

1.0 2.0 0.98 (0.08)

1.0 5.0 0.99 (0.06)

1.0 10.0 0.98 (0.06)

BM Jayawardane, ID McKelvie, SD.Kolev, Talanta 100 (2012) 454.

Analysis of SRM and Natural SamplesAnalysis of SRM and Natural Samples

Determination of Cu(II)

Parameter Optimal valuePVC (%) 49.5

D2EHPA (%) 40.0

DOP (%) 10.0

1-(2’-pyridylazo)-2-naphthol (PAN) (%) 0.5

Hydrophilic zone pH 2 0Hydrophilic zone pH 2.0

Sample volume (µL) 20

Colour development time (min) 15

Sample pH 2 - 7

BM Jayawardane, L dlC Coo, RW.Cattrall, SD.Kolev, Anal. Chim. Acta (submitted).

Calibration of the Card

Linear concentration ranges (mg L-1 Cu) 0.1 – 1.0 / 1.0 – 301

Analytical figures of merit

Detection limit (mg L-1) 0.06

Stability (ambient temperature) > 5 months

Natural samples

No interference up to 30 mg L-1 (1 mg L-1 Cu) of: Fe(III), Al(III), Zn(II), Cd(II),Pb(II), Ca(II) , Mg(II)

Sample Origin AAS

[mg L-1 Cu]

Card

[mg L-1 Cu]( ) ( )

p

Hot water 1 0.70 (0.01) 0.72 (0.01)

Hot water 2 0.24 (0.01) 0.21 (0.02)

Hot water 3 0 26 (0 01) 0 24 (0 02)Hot water 3 0.26 (0.01) 0.24 (0.02)

Hot water 4 1.32 (0.20) 1.11 (0.03)

Mine tailings water 1 7.80 (0.20) 7.56 (0.21)

Mine tailings water 2 7.70 (0.20) 7.55 (0.18)

BM Jayawardane, L dlC Coo, RW.Cattrall, SD.Kolev, Anal. Chim. Acta (submitted).

ConclusionsConclusions

Passive samplers provide valuable information on the time-ass e sa p e s p o de a uab e o at o o t e t eweighted average concentrations of chemical species of interest.

Polymer inclusion membrane (PIM) offer high selectivity, flexibility and sensitivity in passive sampling.

The proposed Cards provide a low-cost, fast and simple platform for the quantitative analysis of aqueous samples forplatform for the quantitative analysis of aqueous samples for nutrients and heavy metals.

The Card approach offers a number of advantages (minimal The Card approach offers a number of advantages (minimal sample and reagent manipulation and consumption, straightforward quantification).

Both techniques could provide valuable analytical information in oceanographic studies at low cost.

AcknowledgmentsAcknowledgments

Professor Robert Cattrall (The University of Melbourne)Principle Research Fellow Ian McKelvie (The University of Melbourne)Professor Wei Shen (Monash University)Associate Professor Lilibeth Coo (University of the Philippines)

l id ( h i i f lb )Dr Ines Almeida (The University of Melbourne)Dr Vincent Pettigrove (Melbourne Water Corporation)Mr. Rhys Coleman (The University of Melbourne)

Mrs. Manori Jayawardane (The University of Melbourne)Ms. Lujia Zhang (The University of Melbourne)Mr Cleopas Chan (The University of Melbourne)Mr. Cleopas Chan (The University of Melbourne)

Australian Research Council (DP1094179 LP110200595)Australian Research Council (DP1094179, LP110200595)Victoria's Science Agenda Investment FundMelbourne Water CorporationMelbourne Water Corporation