FAST GC WITH PID & FUV DETECTORS IN FIELD FAST GC WITH PID & FUV DETECTORS IN FIELD ENENVVIRONMENTALIRONMENTAL ANALANALYYSESSESENENVVIRONMENTAL IRONMENTAL ANALANALYYSESSES

Dr. Jack Driscoll Dr. Jack Driscoll 

PID Analyzers, LLC, Sandwich, MAPID Analyzers, LLC, Sandwich, MA

&

Dr. Philip SmithDr. Philip Smith

USDOL USDOL –– OSHA, Health Response Team, OSHA, Health Response Team, , p ,, p ,

Salt Lake City, UTSalt Lake City, UT

Pittsburgh Conference Paper # Pittsburgh Conference Paper # 180 180 ‐‐ 20P20P

March 2011March 2011March 2011March 2011

Types of SamplesTypes of Samplesyp f pyp f p•• BTEXBTEX

•• Chlorinated HC (TCA TCE PERC MeCl2 )Chlorinated HC (TCA TCE PERC MeCl2 )•• Chlorinated HC (TCA, TCE, PERC, MeCl2…)Chlorinated HC (TCA, TCE, PERC, MeCl2…)

•• Gasoline HC’sGasoline HC’s

•• SolventsSolvents•• ==============================================================

•• Columns selectedColumns selected‐‐ Thick film MS Cap (0.53Thick film MS Cap (0.53mmmm) &  a Gas Pro ) &  a Gas Pro PLOT (PLOT (0.320.32mmmm))

•• ============================================================================================================================

•• Pesticides & PCB’sPesticides & PCB’s‐‐ not considered herenot considered here

•• Better with short (5Better with short (5‐‐10M) thin film capillary column10M) thin film capillary column(( ) p y) p y

DETECTORSDETECTORS‐‐ PID & FUVPID & FUVDETECTORSDETECTORS PID & FUVPID & FUV

PhotoionizationPhotoionization Far UV AbsorbanceFar UV AbsorbancePhotoionizationPhotoionization Far UV AbsorbanceFar UV Absorbance

Comparison of PLOT & Thick Film Comparison of PLOT & Thick Film llColumnsColumns

•• Compare PLOT to Thick Film columns forCompare PLOT to Thick Film columns forCompare PLOT to Thick Film columns for Compare PLOT to Thick Film columns for speed for C1speed for C1‐‐C6 C6 anesanes & & enesenes

•• What are the advantages/disadvantages ofWhat are the advantages/disadvantages of•• What are the advantages/disadvantages of What are the advantages/disadvantages of each?each?

A d f i i l h dA d f i i l h d•• Any advantages of resistively heated Any advantages of resistively heated columns?columns?

HeatupHeatup/cool down? Power utilized?/cool down? Power utilized?

•• Advantages Advantages e.ge.g comparison of comparison of sensitiviitysensitiviitygg gg pp yy

GC312GC312GC312GC312

Portable GCPortable GC 312312 FeaturesFeaturesPortable GCPortable GC‐‐312312 FeaturesFeatures

•• Battery operated Battery operated –– 8 hours8 hours

•• Has external charger orHas external charger orHas external charger or Has external charger or power from car batterypower from car battery

•• Carrier gas supplyCarrier gas supply‐‐ > 25 > 25 hhhourshours

•• 1 or 2 Detectors1 or 2 Detectors

•• PID FID TCD Far UV FPD (SPID FID TCD Far UV FPD (S•• PID, FID, TCD, Far UV, FPD (S PID, FID, TCD, Far UV, FPD (S or P)or P)

•• Temperature ProgrammingTemperature Programming‐‐NEWNEW

GC SchematicGC SchematicGC SchematicGC Schematic

Focus is on the column/oven

Small Small or noor no oven (direct heating of oven (direct heating of column) provides column) provides rapid temperature rapid temperature programming and programming and faster analysesfaster analysesp g gp g g yy

Our DefinitionsOur DefinitionsOur DefinitionsOur Definitions• #1 What is a FAST GC?

A FAST GC h l i ti l h t d l th tA FAST GC h l i ti l h t d l th t•• A FAST GC has a low mass or resistively heated column that A FAST GC has a low mass or resistively heated column that can be heated and/or cooled faster than a conventional ovencan be heated and/or cooled faster than a conventional oven

•• ConditionsConditions--•• Improved heating efficiency is a must for battery operated GCsImproved heating efficiency is a must for battery operated GCs•• Fast GC Fast GC –– run times in 5run times in 5-- 10 minutes instead of 2010 minutes instead of 20--30 minutes 30 minutes • #2 What is a FAST GC column?•• Depends on the application; two examples are:Depends on the application; two examples are:

1. A 15m x 0.32 mm ID, PLOT that is resistively heated & can be 1. A 15m x 0.32 mm ID, PLOT that is resistively heated & can be cooled faster since it has a very small thermal masscooled faster since it has a very small thermal masscooled faster since it has a very small thermal masscooled faster since it has a very small thermal mass

2. A thick film (52. A thick film (5--10 10 µµ) 7.5) 7.5--30 M capillary column that can 30 M capillary column that can separate gases & Solventsseparate gases & Solvents

Power Considerations for a Portable GCPower Considerations for a Portable GCPower Considerations for a Portable GCPower Considerations for a Portable GC

• Clearlyy we do not need a heating rale likeClearlyy,we do not need a heating rale like 8000C/min; we are more concerned with power utilizationpower utilization

FAST GCFAST GC AdvantagesAdvantagesFAST GCFAST GC‐‐AdvantagesAdvantages

• Advantages of FAST GCg

•• Reduced run times Reduced run times 

•• Increased sample throughput Increased sample throughput 

•• Faster turnaround of resultsFaster turnaround of results

•• Improved signal to noise ratioImproved signal to noise ratio

•• Improved detection limits Improved detection limits 

•• Wider range of Wider range of analytesanalytes

•• More samples means a more accurate assessment of the siteMore samples means a more accurate assessment of the site•• More samples means a more accurate assessment of the site More samples means a more accurate assessment of the site 

• Disadvantages of FAST GC

•• More ExpensiveMore ExpensiveMore ExpensiveMore Expensive

•• MinimalMinimal

Resistively Heated Column or Low Resistively Heated Column or Low Mass OvenMass Oven

Agilent Low Mass Column (?)OvenAgilent Low Mass Column (?)OvenAgilent Low Mass Column (?)OvenAgilent Low Mass Column (?)Oven

• The Agilent cap column is wound with Pt wireThe  Agilent cap column is wound with Pt wire that provides the Resistance vs T function that is used to accurately determine theis used to accurately determine the temperature of the column and an additional  wire with a resistance of app 8? Ohms Awire with a resistance of app 8? Ohms. A proportional voltage source (48V) can be used to rapidly heat the column at temperatures ofto rapidly heat the column at temperatures of >1000C/min instead of 100C/min.

ValcoValco Low Mass Column (?) OvenLow Mass Column (?) OvenValcoValco Low Mass Column (?) OvenLow Mass Column (?) Oven

• VICI takes polyimide‐coated fused silica (FST) andVICI  takes  polyimide coated fused silica (FST) and removes  the polyimide layer. Then the (FST) is electroplated with nickel. The resulting nickel‐plated FST tubing  provides  excellent heat transfer to the FST  lining. The Ni tubing is coated with  polyimide  hi h id fl ibilit d l t i l i l tiwhich  provides flexibility and electrical insulation. 

The power is applied to a center tap and the ends are grounded so that the column can be rapidly heatedgrounded so that the column can be rapidly heated at rates up to 80080000C/minC/min instead of 1010‐‐202000C/minC/min

Comparison of Oven Cool Down Comparison of Oven Cool Down timestimes

120Cool down times (Agilent) resistive (blue) & Low mass (red) ovens

80

100

60

80

n Tempe

rature C

Series1

20

40

Oven

Series2

0

0 1 2 3 4 5 6

Cool down minCool down min.

C1 to C6 C1 to C6 AlkanesAlkanes w FUV on 0.32 mm w FUV on 0.32 mm (( f lf l )) llll((5 5 µ µ filmfilm)) CapillaryCapillary

C1 to C3 HC (15 ppm) on 0.32 mm cap at  C1 to C3 HC (15 ppm) on 0.32 mm cap at  l fl (l fl ( / i )/ i )low flow rate( 1.5 low flow rate( 1.5 cccccc/min)/min)

PLOT Column (15M 00.32 mm)with TPPLOT Column (15M 00.32 mm)with TPPLOT Column (15M 00.32 mm)with TPPLOT Column (15M 00.32 mm)with TP

PLOT Column PLOT Column (30M 00 32(30M 00 32(30M 00.32 (30M 00.32 mm)with TPmm)with TP))

AlkanesAlkanes & BTEX on 7u MXT1 w PID& BTEX on 7u MXT1 w PIDAlkanesAlkanes & BTEX on 7u MXT1 w PID& BTEX on 7u MXT1 w PID

Differences Between TF Cap and PLOT for Differences Between TF Cap and PLOT for CC11‐‐CC66 HCHC

•• Main differences are for C1Main differences are for C1‐‐C3 HCC3 HCMain differences are for C1Main differences are for C1 C3 HCC3 HC–– Separation of CHSeparation of CH44 & C& C22HH66‐‐ better on PLOTbetter on PLOT

Separation of CSeparation of C22HH66 & C& C22HH44 better on PLOTbetter on PLOT–– Separation of CSeparation of C22HH66 & C& C22HH44‐‐ better on PLOTbetter on PLOT

–– Separation of CSeparation of C33HH88 & C& C33HH66‐‐ better on PLOTbetter on PLOT

El ti f CEl ti f C t Ct C HCHC h h t TFCh h t TFC–– Elution of  CElution of  C44 to Cto C66 HC HC –– much shorter on TFCmuch shorter on TFC

Comparison of PLOT to Wide Bore Thick Comparison of PLOT to Wide Bore Thick il i i iil i i iFilm Cap sensitivityFilm Cap sensitivity

WCOT Sensitivity Thick Film 7u x 0.53 mm x 7.5M; 15 cc &  35C; PID 0.2 cc inj. X100Compound Run PH

C2H4 25 ppm Avg 3306 cts/ppm

H2S  25 ppm Avg 1453 cts/ppmpp g /pp

Gaspro Sensitivity 30M x 0.32 mm; 5 cc &  35C: PID 0.2cc  inj. X 100C2H4  25 ppm Avg. 1519 cts/ppm 

H2S  25 ppm Avg. 1739 cts/ppm 

SUMMARYSUMMARYSUMMARYSUMMARY• The thick film caps can provide faster analyses with excellent separations 

for a wide variety of HC & solvents  than PLOT columns

• The sensitivity for the thick film column for gases (C2H4 & H2S) is similar to the PLOT

• A Resistively heated column can provide faster analyses than a small GC oven because of its  low mass

• If we program from 30C to 100C, the total time for the RHC is 10 min., whereas, a small oven (fan cooled) will take > 20 min to run this program.

• These two detectors FUV & PID can provide sub ppm or ppb detection of CH4, TCA to the xylenes or decane in air, water or soil (headspace for the latter two)

• If we use a thick film 30M x 0.32 mm column that is resistively heated, we can do most analyses in 10‐12 min and nearly double the volume of samples done in a normal work day.