L5 - Analytical Environmental ChemistryCHM410/1410 Fall...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Analytical Environmental ChemistryCHM410/1410 Fall 2011 Lecture 5 Environmental sampling and data handling Lecture outline Appropriate Quality assurance and Quality Control (QA/QC) measures Sampling Extraction Analysis Figure out all the uncertainties and sources of error Accuracy and Precision Accuracy is the nearness of a measurement of the actual value of the variable being measured. Precision refers to the closeness to each other repeated measurements of the same quantity. Accuracy and Precision Accuracy is the nearness of a measurement of the actual value of the variable being measured. Precision refers to the closeness to each other repeated measurements of the same quantity. Judgmental sampling Environmental sampling Systematic sampling Things to consider: 1. Goal of the sampling campaign • Government monitoring programs vs. academic research studies (exploratory) 2. Where ,when, and how to take samples 3. Size of the samples required • Do you mind non-detects? 4. Number of samples required • Representative of your samples • Replicates Random sampling Random or Judgmental Sampling ? Judgmental Sampling Requires existing information / site knowledge (known point source) Can be quickly implemented and offer greater flexibility Data cannot be used to make predictions of contamination at other sites. Random Sampling Unbiased, but may miss key sites May include too many ‘non-contaminated’ sites and decrease ability to develop contaminant-response relationships Sampling locations at increasing distance from ‘point source’ Consider spatial heterogeneity Reference sites (impact monitoring) Where to sample Before After Control Impact (BACI) Design Before After Water flow Control area Factory Impacted area Control Impact Control Impact When to sample Sediment Sampling Techniques Sediment grab samples Sediment cores How to sample Sediment Sampling Techniques Sediment grab samples • for surface sediment • depth depends on the device How to sample Sediment Sampling Techniques Sediment core samples • Intact or undisturbed sediment samples can be obtained • Can provide temporal variations of chemical along the core Cutting sediment core Measure the sediment core length Outer core - basic parameters Inner core - pore water analysis Temporal PFOS flux (ng/cm-2 d.w.) from 3 stations from Lake Ontario #1034 #1046 #1004 Dating 210Pb activity profile of the sediment core was used to determine the sedimentation rate. The constant rate of supply (CRS) model Sedimentation rate (g cm-2 yr-1 ): #1034: 0.02 – 0.06 #1004: 0.025 – 0.038 #1046: 0.046 – 0.069 The period covered 1950’s – 2000’s Temporal PFOS flux (ng/cm-2 d.w.) from 3 stations from Lake Ontario #1046 #1034 #1004 stn 1046 stn 1034 stn 1004 2006 2006 2006 1996 1996 1996 1986 1986 1986 1976 1976 1976 1966 1966 1966 1956 1956 1946 0.00 0.50 1.00 1 946 1.50 0.00 1956 0.05 0.10 0.15 1946 0.00 PFOS flux ng/cm-2 d.w. 0.10 0.20 0.30 0.40 0.50 14 0.60 Water sampling At which position should we get water samples from a boat? Van dorn water sampler Rosette multiple water sampler with CTD (conductivity, temperature, and depth sensor) Environmental sampling Things to consider: 1. Goal of the sampling campaign • Government monitoring programs vs. academic research studies (exploratory) 2. Where, when, and how to take samples 3. Size of the samples required • Do you mind non-detects? 4. Number of samples required • Representative of your samples • Replicates 250 mL 4L Environmental sampling Things to consider: 1. Goal of the sampling campaign • Government monitoring programs vs. academic research studies (exploratory) 2. Where, when, and how to take samples 3. Size of the samples required • Do you mind non-detects? 4. Number of samples required • Representative of your samples • Replicates • Composite/pooled sample Ort et al. Environmental Science and Technology 2010, 44, 6289. How can you prove your data that are accurate? Sampling Extraction Analysis Appropriate Quality assurance and Quality Control (QA/QC) measures Figure out all the uncertainties and sources of error Quality assurance and Quality Control (QA/QC) measures Before sampling (avoid contamination and loss of target analytes) Suitable sampling device - Contamination will introduce interference into your analysis - Adsorption of the target analytes onto the wall of the sampling device - Rinse your sampling device before use Storage (Integrity of the samples) - Sample bottle - Design (narrow/wide mouth) - Material (glass, polypropylene PP, high density High-density polyethylene HDPE, etc.) - Degradation - Temperature (keep on ice to minimize microbial activities) - UV protection (amber bottle avoid UV degradation Contamination – an analytical chemist’s worst enemy Sampling Extraction Analysis Quality assurance and Quality Control (QA/QC) measures Before sampling (avoid contamination and loss of target analytes) Suitable sampling device - Contamination will introduce interference into your analysis - Adsorption of the target analytes onto the wall of the sampling device - Rinse your sampling device before use Storage (Integrity of the samples: loss of target analyte) - Sample bottle - Design (narrow/wide mouth, volatile chemicals) - Material (glass, polypropylene PP, High-density polyethylene HDPE, etc.) - Degradation - Temperature (keep on ice to minimize microbial activities) - Sunlight protection (amber bottle avoid UV degradation - Oxygen (Oxidation for some metal species, desolved oxygen) Contamination – an analytical chemist’s worst enemy Sampling Extraction Analysis Sample collection summary Container washing procedure Method 1 Method 5 Method 3 Method 4 Method 9 Quality assurance and Quality Control (QA/QC) measures Before sampling (avoid contamination and loss of target analytes) Suitable sampling device - Contamination will introduce interference into your analysis - Adsorption of the target analytes onto the wall of the sampling device - Rinse your sampling device before use Storage (Integrity of the samples) - Sample bottle - Design (narrow/wide mouth, volatile chemicals) - Material (glass, polypropylene PP, High-density polyethylene HDPE, etc.) - Degradation - Temperature (keep on ice to minimize microbial activities) - Sunlight protection (amber bottle avoid UV degradation - Oxygen (Oxidation for some metal species, desolved oxygen) Contamination – an analytical chemist’s worst enemy (always wear glove) Sampling Extraction Analysis Quality assurance and Quality Control (QA/QC) measures During sampling • Sampler blank: any contamination introduced from the sampling device • Field blank: any accidental or incidental (rain or dust contaminants introduced into the samples) contamination • Travel/transport blank: any cross-contamination introduced during transportation or handling. • Storage blank: any cross-contamination introduced during storage process • Positive control: any loss of the target analyte during the sampling process • Field spike control: any loss of the target analyte during the sampling process in the matrix Sampling Extraction Analysis Quality assurance and Quality Control (QA/QC) measures Before Extraction • Instrumental blank: any target analyt presence in the system, how low the detection limit is • Reagent blank: any target analyte presence in the solvent you use • Cartridge blank: any target analyte presence in the cartridge you use for extraction Instrumental blank 4:2/4:2 DiPAPs 4:2/4:2 DiPAPs 4:2/6:2 DiPAPs 4:2/6:2 DiPAPs 6:2/6:2 DiPAPs 6:2/6:2 DiPAPs 6:2/8:2 DiPAPs 6:2/8:2 DiPAPs 8:2/8:2 DiPAPs 8:2/8:2 DiPAPs 8:2/10:2 DiPAPs 8:2/10:2 DiPAPs 10:2/10:2 DiPAPs 10:2/10:2 DiPAPs Sampling Extraction Analysis Quality assurance and Quality Control (QA/QC) measures Before Extraction • Reagent blank: any target analyte presence in the solvent you use Instrumental blank: any target analyt presence in the system, how low the detection limit Instrumental blank is 8 ng/mL DiPAP MeOH 8mL – 0.2mL • Cartridge blank: any target analyte presence in the cartridge you use for extraction standards EMD (Pesticide grade) 4:2/4:2 DiPAPs 4:2/4:2 DiPAPs 4:2/4:2 DiPAPs 6:2/8:2 DiPAPs 6:2/8:2 DiPAPs 4:2/6:2 DiPAPs Not detected 6:2/6:2 DiPAPs 6:2/6:2 DiPAPs 6:2/6:2 DiPAPs Not detected 4:2/6:2 DiPAPs 4:2/6:2 DiPAPs 4:2/6:2 DiPAPs 4:2/4:2 DiPAPs 6:2/6:2 DiPAPs 2.5 pg/mL 6:2/8:2 DiPAPs detected 8:2/8:2 DiPAPs 62 pg/mL 6:2/8:2 DiPAPs 8:2/8:2 DiPAPs 8:2/8:2 DiPAPs 8:2/8:2 DiPAPs 8:2/10:2 DiPAPs 8:2/10:2 DiPAPs 8:2/10:2 DiPAPs 10:2/10:2 DiPAPs 10:2/10:2 DiPAPs 10:2/10:2 DiPAPs Sampling Extraction 8:2/10:2 DiPAPs 10:2/10:2 DiPAPs Analysis detected 5.7 pg/mL Quality assurance and Quality Control (QA/QC) measures Extraction • Extraction/procedural blank: any introduction of contamination and interference in the whole extraction procedure • Procedure recovery: any analytical error or introduction of contamination during the whole extraction procedure • Matrix recovery: any analytical error or introduction of contamination during the whole extraction procedure in your sample matrix, how well the extraction method is for your sample matrix (i.e., ionization suppression or ionization enhancement, coelution of interference) • Quality assurance sample: reproducibility of data the analytical technique /extraction method (i.e., SRM – Standard Reference Materials) Sampling Extraction Analysis Contamination • diPAP contamination of common lab materials brand C • e.g. pipet tips brand B brand A 4:2 diPAP 4:2/6:2 diPAP 6:2 diPAP 6:2/8:2 diPAP 8:2 diPAP 8:2/10:2 diPAP 10:2 diPAP Contamination • Sources of contamination on materials are not fully understood • Packaging materials (e.g. for transfer pipets) • Levels found in these materials: ~150 ng/dm2 Intensity, cps packaging extract 6:2 diPAP 6:2/8:2 diPAP 8:2 diPAP 8:2/10:2 diPAP 10:2 diPAP Quality assurance and Quality Control (QA/QC) measures Extraction • Extraction/procedural blank: any introduction of contamination and interference in the whole extraction procedure • Procedure recovery: any analytical error or introduction of contamination during the whole extraction procedure • Matrix recovery: any analytical error or introduction of contamination during the whole extraction procedure in your sample matrix, how well the extraction method is for your sample matrix (i.e., ionization suppression or ionization enhancement) • Quality assurance sample: reproducibility of data the analytical technique /extraction method (i.e., SRM – Standard Reference Materials) Sampling Extraction Analysis Quality assurance and Quality Control (QA/QC) measures Analysis • Instrumental blank: any target analyte presence in the system, how low the detection limit is • Stability/precision: ensure the measurement are comparable • inject a known concentration standard in every 10 sample injections • evaluate the relative standard deviation of the response (<10) • Quantification: how to report your samples Sampling Extraction Analysis Quantification Standards Conc Analyte (ng/mL) Detector Response Analyte 1 3 5 32 25 120 100 Three different techniques • External calibration • Standard addition • Internal calibration The concentration of the target analyte is calculated based on the response of the sample with those on a standard calibration curve sample from the detector. 420 500 Detector Resonse Sample Conc Analyte (ng/mL) 42 8.2 26 1.2 y = 4.1397x + 8.174 R2 = 0.9984 400 4.3 13 Response of Analyte Samples 300 200 100 0 0 20 40 60 80 Analyte Conc (ng/mL) 100 120 Quantification Standards Three different Advantages: techniques • External calibration • Easynternal calibration •I • Standard addition • Quick Conc Analyte (ng/mL) 1 The concentration of the target analyte is calculated based on the response of the Assumptions sample from the detector with those on a standard • Same response between sample calibration curve. Detector Response Analyte 3 5 32 25 120 100 420 and standard 500 Samples Response of Analyte y = 4.1397x + 8.174 Disadvantages: R = 0.9984 Detector Conc • Ionization suppression Resonse Analyte Sample (ng/mL) • Ionization enhancement 42 • Does not take into 8.2 account for recovery loss 26 1.2 2 300 200 100 4.3 13 400 0 0 20 40 60 80 Analyte Conc (ng/mL) 100 120 Quantification Standards Conc Detector Three different techniques Matrix matched calibration Response Analyte • External calibration (ng/mL) Analyte • Internal calibration • Standard addition 1 3 • Analytical standard is spiked into corresponding matrix (i.e., The concentration of the target 5 32 analyte is etc) at different serum, sandcalculated based on the concentrations 25 120 response of the sample from the 100 420 detector with those on a standard calibration curve. • These matrix matched standards are extracted in the same 500 Detector Resonse Sample Conc Analyte (ng/mL) 42 8.2 26 1.2 y = 4.1397x + 8.174 R2 = 0.9984 400 4.3 13 Response of Analyte way of the samples Samples • A matrix matched calibration curve is made from the matrix matched standards 300 200 100 0 0 20 40 60 80 Analyte Conc (ng/mL) 100 120 Quantification Standards C (Cont’d) Detector Three different techniques Matrix matched calibrationonc Analyte Response • External calibration GoodInternal calibration (ng/mL) Analyte • • Standard addition • Better comparison between the matrix matched calibration 1 3 The concentration the target 5 32 standards and theofbased on the sample analyte is calculated 25 120 r into account from the • Takeesponse of the samplefor recovery loss 100 420 detector with those on a standard calibration curve. Problem Samples y = 4.1397x + 8.174 • Same responses between the matrix matched.9984 calibration R =0 Detector standardsRand the sAConc (assumption) ample esonse nalyte S blank (ng/mL) • No cleanample matrix 42 8.2 26 1.2 400 2 300 200 4.3 13 Response of Analyte 500 100 0 0 20 40 60 80 Analyte Conc (ng/mL) 100 120 Quantification + conc (ng/mL) Detector Response 0 3.2 5 6.2 10 10 50 Three different techniques • External calibration • Standard addition • Internal calibration The concentration of the target analyte is calculated by adding different amounts of the standard into the sample before instrumental analysis 32 Sample alone Sample + 5 ng/mL Sample + 10 ng/mL Sample + 50 ng/mL 40 Detector Response y = 0.571x + 3.5713 R² = 0.9986 Choice of concentration to add is not arbitrary! 30 Need to add 1x, 2x and 10x the concentration of the unknown 20 10 0 -10 0 10 20 30 + Conc (ng/mL) 40 50 60 Quantification Three different techniques • External calibration • Standard addition • Internal calibration The concentration of the target analyte is calculated based on the response factor of the internal/surrogate standard spiked into the sample with with those on a standard calibration curve from the detector . The internal standard is a compound that matches as closely, but not completely, the target analyte in the samples. The signal from the internal standard should be the same for those of the target analyte in the ideal case. (i.e., mass-labelled standard C13, O18) Quantification Conc Internal Standard (ng/mL) Detector Response Analyte Detector Response Internal Standard Response Factor (Analyte/IS) 1 2 3 9.5 0.32 5 2 32 10.5 3.0 25 2 120 10.3 12 100 2 420 9.1 46 Conc techniques Analyte (ng/mL) Three different • External calibration • Standard addition • Internal calibration The concentration of the target analyte is calculated based on the response factor of the internal/surrogate standard spiked into the sample with with those on a standard calibration curve from the detector . Standards Response factor = Detector Response Analyte Detector Response Internal Standard Quantification Standards Conc Internal Standard (ng/mL) Detector Response Analyte Detector Response Internal Standard Response Factor (Analyte/IS) 1 2 3 9.5 0.32 5 2 32 10.5 3.0 25 2 120 10.3 12 100 2 420 9.1 46 Conc techniques Analyte (ng/mL) Three different • External calibration • Standard addition • Internal calibration 50.00 Samples y = 0.4589x + 0.2629 R2 = 0.9997 Detector Response Internal Standard Response Factor 42 5.3 7.9 17 26 10.1 2.6 5.0 13 2 6.5 14 Response Factor 40.00 Detector Response Sample Conc analyte (ng/mL) 30.00 20.00 10.00 0.00 0 20 40 60 80 Analyte Conc (ng/mL) 100 120 e.g. Matrix effect • Co-elution of target compound with interfering substances may over- / under-estimate the concentrations. TDC – interference for PFOS • Disagreement between PFOS concentrations using 499>99 and 499>80 had been reported (Kannan et al., 2001, Wang et al, 2008) F F FF FF F O S OH F O F FF F FF FF F Perfluorooctanesulfonate (PFOS) MW 498.9297 Taurodeoxycholic acid (TDC) MW 498.2968 TDC – interference for PFOS • Disagreement between PFOS concentrations using 499>99 and 499>80 had been reported (Kannan et al., 2001, Wang et al, 2008) 100% 100% 1. Possible co-eluting interferences with PFOS, such as TDC has been reported in a recent study (Benskin et al., 2007). 100%TDC is an endogenous sulfonic acid which 2. is formed in the liver by conjugation of deoxycholate with taurine which has a similar mass (498.2968) with PFOS (498.9297). 100% 3. The problems between PFOS and TDC were that first, they co-elute at similar time in a C18 column. 100% 100% 100% 100% C18 Betasil column, flow rate 0.3mL/min Ion exchange JJ50 -2Dcolumn, flow rate 0.3mL/min TDC – interference for PFOS • Disagreement between PFOS concentrations using 499>99 and 499>80 had been reported (Kannan et al., 2001, Wang et al, 2008) 100% 100% 100% 100% 100% 100% 100% 100% C18 Betasil column, flow rate 0.3mL/min Ion exchange JJ50 -2Dcolumn, flow rate 0.3mL/min TDC – interference for PFOS • Disagreement between PFOS concentrations using 499>99 and 499>80 had been reported (Kannan et al., 2001, Wang et al, 2008) 100% 100% If the PFOS concentrations were quantified using 499>80 without proper separation, overestimation may result. 100% 100% 100% 100% 100% 100% C18 Betasil column, flow rate 0.3mL/min Ion exchange JJ50 -2Dcolumn, flow rate 0.3mL/min PFOS and TDC in different blood samples TDC PFC mixR 1b PFC mixR 1b PFOS 100 PFC mixR 1b 100 100 % PFOS2 Std 498.8>79.8 PFOS Std 498.8>79.8 PFOS Std 498.8>79.8 PFC mixR 1b % 100 %0 0 % 100 PFC mixR 1b 0 100 0 100 % 100 % %0 1. TDC was detected in some of the blood samples 2. TDC could be separated from PFOS using JJ ion exchange column TDC Std 498.8>79.8 TDC Std 498.8>79.8 TDC Std 498.8>79.8 PFOS Std 498.8>79.8 % 0 100 0 Chicken 498.8>79.8 Cat 498.8>79.8 >79.8 Chicken 498.8 >79.8 TDC Std 498.8 PFC mixR 1b 0 100 100 % 100 100 %0 % % 100 0 0 0 0 Chicken A3 498.8>79.8 Chicken A3 498.8>79.8 498.8>79.8 Mouse 4Std 498.8>79.8 PFOS2 98.8>79.8 %0 PFC mixR 1b PFC mixR 1b 100 100 100 % 100 100 % % % % 100 0 0 0 100 100 100 0 1000 % % 100 % % 100 %0 0 0 0 % 100 0 % 100 100 100 % 0 % % 0 1000 % 100 0 0 100 100 % % % 100 % % 0 0 %0 0 0 100 0 100 100 0 100 % % % Chickentd 498.8>79.8 PFOS S A5 498.8>79.8 Cow 498.8>79.8 Chicken A3 498.8>79.8 Chicken A5 498.8>79.8 Pig 498.8>79.8 TDC Std 498.8>79.8 Time 2.00 4.00 6.00 SheepStd 498.8>79.8 TDC498.8>79.8 Dog 498.8>79.8 Sheep 498.8498.8>79.8 Chicken A5 >79.8 8.00 10.00 12.00 14.00 16.00 18.00 20.00 22.00 24.00 26.00 28.00 Pig 4498.8>79.8 Cat 98.8>79.8 Horse 498.8>79.8 Chicken 498.8>79.8 Horse 498.8>79.8 Sheep 2.00 2.00 2.00 4.00 4.00 4.00 6.00 6.00 6.00 Mouse 498.8>79.8 >79.8 2.00 4.00 Chicken A3 498.8 6.00 Horse 498.8>79.8 Time 8.00 10.00 12.00 14.00 16.00 18.00 8.00 8.00 10.00 10.00 12.00 12.00 14.00 14.00 16.0016.00 18.00 20.00 18.00 20.00 22.00 20.00 22.00 24.00 22.00 24.00 26.00 24.00 26.00 28.00 26.0028.00 Time 28.00 Time 8.00 10.00 12.00 14.00 16.00 18.00 20.00 22.00 24.00 26.00 28.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00 22.00 24.00 26.00 28.00 0 0 100 0 100 2.00 4.00 6.00 Pig 498.8>79.8 Chicken A5 498.8>79.8 % % 0 0 100 100 % % 0 Sheep 498.8>79.8 Pig 498.8>79.8 Time Time PFOS and TDC in different blood samples TDC PFC mixR 1b PFC mixR 1b PFOS 100 PFC mixR 1b 100 100 % PFOS2 Std 498.8>79.8 PFOS Std 498.8>79.8 PFOS Std 498.8>79.8 PFC mixR 1b % Compound n TDC Std 498.8>79.8 TDC Std 498.8>79.8 TDC Std 498.8>79.8 PFOS PFOSStd 498.8>79.8 498.8>98.8 Chicken 498.8>79.8 PFOS 498.8>79.8 Cat 498.8>79.8 >79.8 Chicken 498.8 >79.8 TDC Std 498.8 TDC 498.3>123.8 Chicken A3 498.8>79.8 TDC 498.3>106.8 Chicken A3 498.8>79.8 498.8>79.8 Mouse 4Std 498.8>79.8 TDC 498.3>79.9 PFOS2 98.8>79.8 Cat 1 616 668 35 40 42 100 %0 0 % 100 PFC mixR 1b 0 100 0 100 % 100 % %0 % 0 100 0 PFC mixR 1b 0 100 100 % 100 100 %0 % % 100 0 0 0 0 PFC mixR 1b 100 100 100 % 100 100 % % %0 PFC mixR 1b % % 100 0 0 0 100 Chicken 3 <50 <50 128-573 165-570 195-772 Cow 1 165 181 52 50 60 Dog 1 643 703 37 47 55 Horse Mouse Pig Sheep 3 1. 1TDC was2detected in some of1 <50 blood -270 153-196 <50 the <50 samples <50-283 156-183 < 2.<50 TDC could be separated from50 23 FOS using JJ ion <10 <10 P exchange 24 31 olumn <10 <10 28 c 35 <10 <10 29 Chickentd 498.8>79.8 PFOS S A5 498.8>79.8 Cow 498.8>79.8 Chicken A3 498.8>79.8 Chicken A5 498.8>79.8 Pig 498.8>79.8 TDC Std 498.8>79.8 TDC concentrations in one of the chicken blood samples: 100 100 0 1000 % % 100 % % 100 %0 0 0 0 % 100 0 % 100 100 100 % 0 % % 0 1000 % 100 0 0 100 100 % % % 100 % % 0 0 %0 0 0 100 0 100 100 0 100 % % % Time 2.00 4.00 6.00 SheepStd 498.8>79.8 TDC498.8>79.8 Dog 498.8>79.8 Sheep 498.8498.8>79.8 Chicken A5 >79.8 8.00 10.00 12.00 14.00 16.00 18.00 20.00 22.00 24.00 26.00 28.00 Pig 4498.8>79.8 Cat 98.8>79.8 Horse 498.8>79.8 Chicken 498.8>79.8 Horse 498.8>79.8 Sheep 2.00 2.00 2.00 4.00 4.00 4.00 6.00 6.00 6.00 Mouse 498.8>79.8 >79.8 2.00 4.00 Chicken A3 498.8 6.00 Horse 498.8>79.8 Time 8.00 10.00 12.00 14.00 16.00 18.00 8.00 8.00 10.00 10.00 12.00 12.00 14.00 14.00 16.0016.00 18.00 20.00 18.00 20.00 22.00 20.00 22.00 24.00 22.00 24.00 26.00 24.00 26.00 28.00 26.0028.00 Time 28.00 Time 8.00 10.00 12.00 14.00 16.00 18.00 20.00 22.00 24.00 26.00 28.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00 22.00 24.00 26.00 28.00 0 0 100 0 100 2.00 4.00 6.00 Pig 498.8>79.8 Chicken A5 498.8>79.8 % % 0 0 100 100 % % 0 Sheep 498.8>79.8 Pig 498.8>79.8 Time Time PFOS and TDC in different blood samples TDC PFC mixR 1b PFC mixR 1b PFOS 100 PFC mixR 1b 100 100 % PFOS2 Std 498.8>79.8 PFOS Std 498.8>79.8 PFOS Std 498.8>79.8 PFC mixR 1b % Compound n TDC Std 498.8>79.8 TDC Std 498.8>79.8 TDC Std 498.8>79.8 PFOS PFOSStd 498.8>79.8 498.8>98.8 Chicken 498.8>79.8 PFOS 498.8>79.8 Cat 498.8>79.8 >79.8 Chicken 498.8 >79.8 TDC Std 498.8 TDC 498.3>123.8 Chicken A3 498.8>79.8 TDC 498.3>106.8 Chicken A3 498.8>79.8 498.8>79.8 Mouse 4Std 498.8>79.8 TDC 498.3>79.9 PFOS2 98.8>79.8 Cat 1 616 668 35 40 42 100 %0 0 % 100 PFC mixR 1b 0 100 0 100 % 100 % %0 % 0 100 0 PFC mixR 1b 0 100 100 % 100 100 %0 % % 100 0 0 0 0 PFC mixR 1b 100 100 100 % 100 100 % % %0 PFC mixR 1b % % 100 0 0 0 100 Chicken 3 <50 <50 128-573 165-570 195-772 Cow 1 165 181 52 50 60 Dog 1 643 703 37 47 55 Horse Mouse Pig Sheep 3 1. 1TDC was2detected in some of1 <50 blood -270 153-196 <50 the <50 samples <50-283 156-183 < 2.<50 TDC could be separated from50 23 FOS using JJ ion <10 <10 P exchange 24 31 olumn <10 <10 28 c 35 <10 <10 29 Chickentd 498.8>79.8 PFOS S A5 498.8>79.8 Cow 498.8>79.8 Chicken A3 498.8>79.8 Chicken A5 498.8>79.8 Pig 498.8>79.8 TDC Std 498.8>79.8 TDC concentrations in one of the chicken blood samples: 100 100 0 1000 % % 100 % % 100 %0 0 0 0 % 100 0 % 100 100 100 % 0 % % 0 1000 % 100 0 Time 2.00 4.00 6.00 SheepStd 498.8>79.8 TDC498.8>79.8 Dog 498.8>79.8 Sheep 498.8498.8>79.8 Chicken A5 >79.8 8.00 10.00 12.00 14.00 16.00 18.00 20.00 22.00 • ion pair: 772 pg/mL, • formic acid: 873 pg/mL, and • ACN: 850 pg/mL) 0 100 100 % % % 100 % % 0 0 %0 0 0 100 0 100 100 0 100 % % % 24.00 26.00 28.00 Pig 4498.8>79.8 Cat 98.8>79.8 Horse 498.8>79.8 Chicken 498.8>79.8 Horse 498.8>79.8 Sheep 2.00 2.00 2.00 4.00 4.00 4.00 6.00 6.00 6.00 Mouse 498.8>79.8 >79.8 2.00 4.00 Chicken A3 498.8 6.00 Horse 498.8>79.8 8.00 10.00 12.00 14.00 16.00 18.00 8.00 8.00 10.00 10.00 12.00 12.00 14.00 14.00 16.0016.00 18.00 20.00 18.00 20.00 Time 22.00 20.00 22.00 24.00 22.00 24.00 26.00 24.00 26.00 28.00 26.0028.00 Time 28.00 Time 8.00 10.00 12.00 14.00 16.00 18.00 20.00 22.00 24.00 26.00 28.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00 22.00 24.00 26.00 28.00 0 0 100 0 100 2.00 4.00 6.00 Pig 498.8>79.8 Chicken A5 498.8>79.8 % % 0 0 100 100 % % 0 Sheep 498.8>79.8 Pig 498.8>79.8 Time Time PFOS and TDC in different blood samples TDC PFC mixR 1b PFC mixR 1b PFOS 100 PFC mixR 1b 100 100 % PFOS2 Std 498.8>79.8 PFOS Std 498.8>79.8 PFOS Std 498.8>79.8 PFC mixR 1b % Compound n TDC Std 498.8>79.8 TDC Std 498.8>79.8 TDC Std 498.8>79.8 PFOS PFOSStd 498.8>79.8 498.8>98.8 Chicken 498.8>79.8 PFOS 498.8>79.8 Cat 498.8>79.8 >79.8 Chicken 498.8 >79.8 TDC Std 498.8 TDC 498.3>123.8 Chicken A3 498.8>79.8 TDC 498.3>106.8 Chicken A3 498.8>79.8 498.8>79.8 Mouse 4Std 498.8>79.8 TDC 498.3>79.9 PFOS2 98.8>79.8 Cat 1 616 668 35 40 42 100 %0 0 % 100 PFC mixR 1b 0 100 0 100 % 100 % %0 % 0 100 0 PFC mixR 1b 0 100 100 % 100 100 %0 % % 100 0 0 0 0 PFC mixR 1b 100 100 100 % 100 100 % % %0 PFC mixR 1b % % 100 0 0 0 100 Chicken 3 <50 <50 128-573 165-570 195-772 Cow 1 165 181 52 50 60 Dog 1 643 703 37 47 55 Horse Mouse Pig Sheep 3 1. 1TDC was2detected in some of1 <50 blood -270 153-196 <50 the <50 samples <50-283 156-183 < 2.<50 TDC could be separated from50 23 FOS using JJ ion <10 <10 P exchange 24 31 olumn <10 <10 28 c 35 <10 <10 29 Chickentd 498.8>79.8 PFOS S A5 498.8>79.8 Cow 498.8>79.8 Chicken A3 498.8>79.8 Chicken A5 498.8>79.8 Pig 498.8>79.8 TDC Std 498.8>79.8 TDC concentrations in one of the chicken blood samples: 100 100 0 1000 % % 100 % % 100 %0 0 0 0 % 100 0 % 100 100 100 % 0 % % 0 1000 % 100 0 Time 2.00 4.00 6.00 SheepStd 498.8>79.8 TDC498.8>79.8 Dog 498.8>79.8 Sheep 498.8498.8>79.8 Chicken A5 >79.8 8.00 10.00 12.00 14.00 16.00 18.00 20.00 22.00 24.00 26.00 28.00 • ion pair: 772 pg/mL, • formic acid: 873 pg/mL, and • ACN: 850 pg/mL) false-positive identification regardless of the extraction methods used. 0 100 100 % % % 100 % % 0 0 %0 0 0 100 0 100 100 0 100 % % % Pig 4498.8>79.8 Cat 98.8>79.8 Horse 498.8>79.8 Chicken 498.8>79.8 Horse 498.8>79.8 Sheep 2.00 2.00 2.00 4.00 4.00 4.00 6.00 6.00 6.00 Mouse 498.8>79.8 >79.8 2.00 4.00 Chicken A3 498.8 6.00 Horse 498.8>79.8 Time 8.00 10.00 12.00 14.00 16.00 18.00 8.00 8.00 10.00 10.00 12.00 12.00 14.00 14.00 16.0016.00 18.00 20.00 18.00 20.00 22.00 20.00 22.00 24.00 22.00 24.00 26.00 24.00 26.00 28.00 26.0028.00 Time 28.00 Time 8.00 10.00 12.00 14.00 16.00 18.00 20.00 22.00 24.00 26.00 28.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00 22.00 24.00 26.00 28.00 0 0 100 0 100 2.00 4.00 6.00 Pig 498.8>79.8 Chicken A5 498.8>79.8 % % 0 0 100 100 % % 0 Sheep 498.8>79.8 Pig 498.8>79.8 Time Time Conclusions • Different extraction methods (i.e., ion pair, formic acid and ACN) with WAX SPE cleanup did not minimize the extraction of the possible interference, TDC, from the whole blood samples. • The use of confirmation ion or 13C-labelled standards did not reduce matrix effect. • Only high resolution separation of target analytes from the interference before mass spectrometric analysis can reduce the systematic error caused by different transitions or MS/MS. • The use of the ion exchange column (JJ50-2D) can separate TDC from PFOS and enable accurate measurement of PFOS in the sample. Conclusions • The optimized ACN extraction method with WAX SPE cleanup can allow the extraction of more than 28 PFCs in whole blood samples. • Different extraction methods mass transitions Not only using different(i.e., ion pair, formic acid and ACN) with WAX SPE cleanup did not minimize the extraction of the (qualifying and quantification ions), but also possible interference, TDC, from the whole blood samples. • The use of confirmation ion or 13C-labeled standards did not reduce different effect. matrix stationary phases or high resolution mass • Only high resolution separation ccurate identification and spectroscopy can enable aof target analytes from the interference before mass spectrometric analysis can reduce the quantification of PFCs. systematic error caused by different transitions or MS/MS. • The use of the ion exchange column (JJ50-2D) can separate TDC from PFOS and enable accurate measurement of PFOS in the sample. Probability Normal distribution µ -3σ -2σ -1σ µ - mean σ - standard deviation 1σ 2σ 3σ 0σ 1σ 2σ 3σ Some Definitions Arithmetic mean Geometric mean Appropriate for normally distributed data Appropriate for log normally distributed data Standard deviation Standard error Describes scatter in the data/ population Report your data: 100 ± 10 mg/L Describes uncertainty around the mean/ standard deviation of the mean What does is mean? ...
View Full Document

Ask a homework question - tutors are online