Table of Contents

Locator Record

Title: Aflatoxin B1-lysine concentration in serum (SSAFB_A )
Contact Number: 1-866-441-NCHS
Years of Content: 1999 - 2000
First Published: August, 2012
Revised: NA
Access Constraints: None
Use Constraints: None
Geographic Coverage: National
Subject:Aflatoxin B1-lysine concentrations in serum in the U.S. population
Record Source: NHANES 1999 - 2000
Survey Methodology: NHANES 1999 - 2000 is a stratified multistage probability sample of the civilian non-institutionalized population of the U.S.
Medium: NHANES Web site; SAS transport files

Component Description

Measurement of concentrations (ng/mL) of aflatoxin B1-lysine, derived from aflatoxin B1-albumin adducts, in a 2,104 serum sample subset of NHANES 1999-2000.

Eligible Sample

A one-third subset of examined participants ≥ 12 years of age from NHANES 1999-2000.

Description of Laboratory Methodology

Measurement of serum aflatoxin-albumin adducts

Modification of the method of McCoy et al. (2005) was used to assess aflatoxin-albumin adducts in serum. NHANES serum specimens were obtained from McKesson Plasma and Biologics (San Francisco, CA) where they were stored at –70°C; specimens were residual sera that were previously freeze/thawed one or more times. In brief, the laboratory used a high throughput method in which 250µL serum was robotically aliquoted into 96-well plates and spiked with 100µL of tetradeuterated internal standard (aflatoxin B1-lysine-d4) to account for recovery. Aflatoxin B1 adducts were hydrolyzed from serum albumin using enzymatic digestion with pronase which was incubated in a 40°C water bath for 4 hours or overnight at 37°C. Once digestion was complete, samples were transferred to an automated solid phase extraction (SPE) system.

The method employed a mixed-mode anion exchange sorbent in an automated SPE of AFB1-lysine (AFB-lys) resulting from the enzymatic hydrolysis of serum albumin. SPE columns were eluted with 2% formic acid in methanol. An isotope dilution mass spectrometry based method (LC-MS/MS triple quadrupole MS using electrospray ionization) was used for routine quantitation of AFB-lys as a measure of individual exposure to aflatoxin B1.

Concentrated samples were injected onto a C18 HPLC chromatographic column and eluted with a gradient of acetonitrile in water with 0.06% formic acid to resolve the AFB-lys from other matrix constituents. Analytes were detected using positive ionization selective reaction monitoring mode and quantified using 4-point linear calibration curves that used 1/x2 weighting; quantitation was based on peak area ratios using the internal standard to correct for recovery. Peak area ratios (aflatoxin B1-lysine m/z: aflatoxin B1-lysine-d4 m/z) were linearly related to concentration. Instrument voltages and temperatures were optimized to yield optimum intensity of AFB-lys, as previously published. AFB-lys concentrations were quantitated in a subset of NHANES 1999-2000 serum specimens in 62 separate assays.

Transitions for aflatoxin B1-lysine (AFB-lys) and deuterated internal standard
Analyte Q1 (Da) Q3 (Da)
Aflatoxin B1-lysine 457.3 394.2
Aflatoxin B1-lysine-d4 461.3 398.3

The average (±SD) calibration slope for assays containing NHANES samples was 1.1±0.2 and average intercept was 0.0047±0.016. Calibration curves had an average (±SD) r2 of 0.999±0.008. Calibrators were required to be within 15% of their nominal values for all assays in which results above the lower limit of detection were reported. Two different calibration ranges were used; the lower range was used in the majority of the NHANES analyses.

 

Four calibration standards (ng/mL) used in 62 assays to measure serum concentrations of aflatoxin B1-lysine (AFB-lys) in NHANES 1999-2000
No. Assays Calibrator 1 Calibrator 2 Calibrator 3 Calibrator 4
6 0.07 0.34 0.68 2.73
56 0.01 0.05 0.5 1.5

 Blanks were analyzed concurrently with unknown samples and were used to determine if any analyte contamination had occurred. Blanks contained 250µL 25% methanol in place of serum; one blank was included in each assay. In none of the 62 assays containing NHANES samples, was AFB-lys detectable in the blank.

Relative retention times were used to select the correct peaks for integration and quantitation. AFB-lys eluted 0.02±0.01 min after the internal standard in the QC pools which were known to contain aflatoxin B1-albumin adducts and similarly, 0.02±0.02 min after the internal standard in the unknown NHANES samples. Peaks greater than 0.06 minutes from the internal standard were not considered to be representing AFB-lys.

Limit of Detection (LOD)

Using a combination of approaches, the lower limit of detection (LOD) was determined to be 0.02 ng/mL. Results near the LOD are subject to greater uncertainty. Several schemes were used to estimate the LOD including 1) Taylor series to estimate the SD of a zero sample via extrapolation of a linear dilution series to zero concentration, 2) visual evaluation of chromatography around the LOD, and 3) estimation of the LOD by calculating 3 times the s0 where s0 is the standard deviation of the concentration of a near-background sample that was measured multiple times.

Summary of activities to estimate the lower limit of detection (LOD) for AFB-lys in serum using a LC-MS/MS assay
Date of Analysis LOD Scheme Design Estimate of LOD (ng/mL)
Aug-06 Taylor series (3*SD of a zero sample) 5 dilutions, singlicates per dilution over 3 days (15 points) 0.018
Feb-07 Taylor series (3*SD of a zero sample) 3 dilutions, 5 replicates per dilution over 3 days (45 points); also evaluated chromatography for appropriateness 0.018
Jan-08 Chromatographic evaluation Evaluated 7 chromatograms at about 0.02, 0.48, 1.5 ng/mL for appropriateness of 0.02 ng/mL 0.02
Aug-10 3*SD of a sample close to zero Nearly zero sample, singlicate over 3 days (3 points) 0.04
Feb-12 Chromatographic evaluation Evaluated 27 chromatograms =LOD from NHANES and dozens 0.02

Standard stability

A concentrated stock standard solution stored at -70°C was diluted to an intermediate concentration that was further diluted and used to prepare individual calibrators. The highly concentrated stock material, synthetic AFB-lys, was purified using semipreparative HPLC-UV. Stability of this stock solution over the course of 7 years was periodically determined. Degradation was no more than 2%. Calibrators were adjusted accordingly after each determination.

 

Stability of the concentrated stock of AFB-lys stored at -70°C
Date of analysis [AFB-lys] µg/mL
Jul-04 4.23
Oct-07 4.19
Jun-11 4.17

 To test for stability of the intermediate stock standard solutions that were diluted from the concentrated stock, we stored materials at -20°C or -70°C for up to 2 years. We demonstrated complete stability at -70°C. 

Stability of the intermediate stocks of AFB-lys stored at -20°C or -70°C
Initial[AFB-lys] ng/mL Storage temperature Storage time Stability
50 -20°C 3 mo 90%
4 -70°C 2 yr 100%

Serum stability

To test for stability of aflatoxin-albumin adducts in serum, high (HS04501) and low (LS04500) bench QC pools were stored at variable temperatures and times; AFB-lys concentrations were compared to concentrations in pools that were continuously stored at -70°C for 3.3 years. Pools stored at -20°C or 4°C for 1.6 years, or 37°C for 0.25 years showed no evidence of degradation. QC serum maintained at room temperature for 16 h prior to sample processing for quantitative analysis showed no evidence of degradation.

QC pools were also submitted to three freeze/thaw cycles and subsequently analyzed within a single analytical run. On average, there appeared to be a small decrease in the AFB-lys concentrations (average 97±2% of expected result) over the course of three cycles but all concentrations from freeze-thaw samples were within QC limits thus indicating no significant decrease could be established.

From the literature, Scholl and Groopman reported that using two closely comparable chromatographic methods (LC-MS/MS and HPLC-fluorescence), a set of 19 serum specimens with AFB-lys concentrations ranging from 0.3 to 6 ng/mL stored for 15 years at -80°C, gave AFB-lys results that were essentially unchanged; currently, this appears to be the longest term demonstration of aflatoxin-albumin adduct stability in serum.

Reproducibility

Approximately 75 percent of the NHANES samples (1,572/2,104) were tested once for AFB-lys. Considering all NHANES samples, of those with AFB-lys results greater than or equal to the LOD (27/2,104), 93 percent (25/27 cases) were measured more than once to attempt to confirm the finding; only those with insufficient serum were not retested (2/27 cases). Because most positive results were around the LOD and because of the inherent variability of results around the LOD (>30% CVanalytical), we expected inconsistency in repeating and confirming results. Confirmation was considered achieved if a subsequent result was ≥LOD. We defined AFB-lys-positive samples having at least one result that conformed to the relative retention time requirement for AFB-lys peak selection (see earlier). Thus, not all AFB-lys-positive results were confirmed, however, all of the highest results (>0.05 ng/mL) were repeated and confirmed (see following table).

Repeat analysis of 27 AFB-lys-positive samples grouped by concentration at or grouped above the LOD (0.02 ng/mL)
[AFB-lys] ng/mL N ≥LOD Confirmed
0.02 7 1/7 (14%)
0.03 - 0.05 15 8/15 (53%)
0.06 - 0.20 5 5/5 (100%)

Data Processing and Editing

Data were received after all the laboratory testing was complete. The data were not edited for extreme values.

Data Access: All final data are publicly available.

Laboratory Quality Assurance and Monitoring

The laboratory and method were certified according to the Clinical Laboratory Improvement Amendment (1988) guidelines.

Units of serum were obtained from Tennessee Blood Services (Memphis, TN) and were screened using the methodology described above; all units of serum that were screened exhibited undetectable AFB-lys. All quality control pools were prepared by spiking human serum with serum from rats that were dosed with aflatoxin B1 to create aflatoxin B1-albumin adducts. Targeted concentrations of AFB-lys were estimated and confirmed before dispensing the blended serum pools into 2-mL cryovials for storage at -70°C.

Before each analytical run, individual calibration standards, bench QC materials and serum samples were thawed from -70°C to room temperature. Calibrators and QC materials were prepared and analyzed in parallel with the NHANES samples.

Typical assays consisted of 4 calibration samples, 1 blank, 3 bench quality control samples, 53 subject person’s serum followed by 3 bench quality control samples. One in every 20 subject person’s serum in the assay was a random blind QC pool.

 

Blind Quality Control

Three blind QC pools were used during the analysis of the survey specimens. Their results were required to be within 3 standard deviations of the characterization means. At the end of the study, summary statistics were tabulated for the blind QC pools that were included in the 62 assays from this study.

The following two tables show the mean, standard deviation of individual results (SDi) and analytical coefficient of variation (CVa) for aflatoxin B1-lysine concentrations (ng/mL) from individual blind quality control pools during the characterization period and during the period of analysis of NHANES samples

Blind quality control pools during the characterization period
Blind QC Pools Mean SDi CVa
High 4.22 0.34 8%
Medium 1.55 0.12 8%
Low 0.49 0.06 11%

Blind quality control pools during NHANES Analysis
Blind QC Pools Mean SDi CVa
High 4.22 0.35 8%
Medium 1.53 0.01 9%
Low 0.48 0.04 9%

 

Bench Quality Control

Five bench QC pools, prepared as described above, were characterized to determine the quality control limits for duplicate samples. After establishment of the control limits of the pools, QC samples contained within each analytical run were evaluated for validity by use of a multi-rule quality control SAS program. Each analytical run contained 2-3 pools in duplicate.

The following two tables show the mean, standard deviation of pair mean (SDm) and analytical coefficient of variation (CVa) for aflatoxin B1-lysine concentrations (ng/mL) in bench quality control pools during characterization period and during the period of analysis of NHANES samples

Bench quality control pools during the characterization period
Bench QC Pools Mean SDm CVa
HS04501_QC03S 1.63 0.11 7%
HS07502_QC01S 1.03 0.05 5%
MS07501_QC01S 0.65 0.03 5%
LS04500_QC03S 0.26 0.02 8%
LS07500_QC01S 0.2 0.02 8%

Bench quality control pools during NHANES Analysis
Bench QC Pools Mean SDm CVa
HS04501_QC03S 1.65 0.13 8%
HS07502_QC01S 1.03 0.1 10%
MS07501_QC01S 0.64 0.04 6%
LS04500_QC03S 0.26 0.03 10%
LS07500_QC01S 0.2 0.02 11%

 External Quality Assurance

As an external quality assurance activity, a sample exchange was conducted to assess the comparability of three different methods for measuring serum AFB-lys concentrations. Published results showed that isotope dilution LC-MS/MS was the most sensitive technique and HPLC-fluorescence was the least sensitive method. Overall, this exchange showed excellent correlations among the three independent methodologies, including ELISA, which were conducted in different laboratories. The two chromatographic methods showed satisfactory agreement (LC-MS/MS = HPLC-fluorescence ÷ 0.71). In summary, the results supported the validation of these technologies for assessment of human exposure to this environmental toxin and carcinogen.

Analytic Notes

None.

References

Codebook and Frequencies

SEQN - Respondent sequence number

Variable Name:
SEQN
SAS Label:
Respondent sequence number
English Text:
Respondent sequence number.
Target:
Both males and females 12 YEARS - 150 YEARS

SSAFB - Aflatoxin B1-lysine result (ng/mL)

Variable Name:
SSAFB
SAS Label:
Aflatoxin B1-lysine result (ng/mL)
English Text:
Aflatoxin B1-lysine result (ng/mL)
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.01 to 0.2 Range of Values 2090 2090
. Missing 13 2103

SSAFBLC - Aflatoxin B1-lysine result comment code

Variable Name:
SSAFBLC
SAS Label:
Aflatoxin B1-lysine result comment code
English Text:
Aflatoxin B1-lysine result comment code
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 detectable result 27 27
1 below detectable limit 2063 2090
. Missing 13 2103

WTSPH4YR - Phthalate Subsample 4 Year Mec Weight

Variable Name:
WTSPH4YR
SAS Label:
Phthalate Subsample 4 Year Mec Weight
English Text:
Phthalate Subsample 4 year Mec
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 308716.27489 Range of Values 2103 2103
. Missing 0 2103

WTSPH2YR - Phthalate Subsample 2 Year Mec Weight

Variable Name:
WTSPH2YR
SAS Label:
Phthalate Subsample 2 Year Mec Weight
English Text:
Phthalate Subsample 2 year Mec Weight
English Instructions:
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 784084.01503 Range of Values 2103 2103
. Missing 0 2103

WTSPH01 - Phthalate Mec Weight Jack Knife Rep 01

Variable Name:
WTSPH01
SAS Label:
Phthalate Mec Weight Jack Knife Rep 01
English Text:
Phthalate Mec Weight Jack Knife Rep 01
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 765268.18045 Range of Values 2103 2103
. Missing 0 2103

WTSPH02 - Phthalate Mec Weight Jack Knife Rep 02

Variable Name:
WTSPH02
SAS Label:
Phthalate Mec Weight Jack Knife Rep 02
English Text:
Phthalate Mec Weight Jack Knife Rep 02
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 779596.23803 Range of Values 2103 2103
. Missing 0 2103

WTSPH03 - Phthalate Mec Weight Jack Knife Rep 03

Variable Name:
WTSPH03
SAS Label:
Phthalate Mec Weight Jack Knife Rep 03
English Text:
Phthalate Mec Weight Jack Knife Rep 03
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 784169.09415 Range of Values 2103 2103
. Missing 0 2103

WTSPH04 - Phthalate Mec Weight Jack Knife Rep 04

Variable Name:
WTSPH04
SAS Label:
Phthalate Mec Weight Jack Knife Rep 04
English Text:
Phthalate Mec Weight Jack Knife Rep 04
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 792866.41129 Range of Values 2103 2103
. Missing 0 2103

WTSPH05 - Phthalate Mec Weight Jack Knife Rep 05

Variable Name:
WTSPH05
SAS Label:
Phthalate Mec Weight Jack Knife Rep 05
English Text:
Phthalate Mec Weight Jack Knife Rep 05
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 780507.40019 Range of Values 2103 2103
. Missing 0 2103

WTSPH06 - Phthalate Mec Weight Jack Knife Rep 06

Variable Name:
WTSPH06
SAS Label:
Phthalate Mec Weight Jack Knife Rep 06
English Text:
Phthalate Mec Weight Jack Knife Rep 06
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 803223.95634 Range of Values 2103 2103
. Missing 0 2103

WTSPH07 - Phthalate Mec Weight Jack Knife Rep 07

Variable Name:
WTSPH07
SAS Label:
Phthalate Mec Weight Jack Knife Rep 07
English Text:
Phthalate Mec Weight Jack Knife Rep 07
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 768135.8023 Range of Values 2103 2103
. Missing 0 2103

WTSPH08 - Phthalate Mec Weight Jack Knife Rep 08

Variable Name:
WTSPH08
SAS Label:
Phthalate Mec Weight Jack Knife Rep 08
English Text:
Phthalate Mec Weight Jack Knife Rep 08
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 779055.05256 Range of Values 2103 2103
. Missing 0 2103

WTSPH09 - Phthalate Mec Weight Jack Knife Rep 09

Variable Name:
WTSPH09
SAS Label:
Phthalate Mec Weight Jack Knife Rep 09
English Text:
Phthalate Mec Weight Jack Knife Rep 09
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 794668.1316 Range of Values 2103 2103
. Missing 0 2103

WTSPH10 - Phthalate Mec Weight Jack Knife Rep 10

Variable Name:
WTSPH10
SAS Label:
Phthalate Mec Weight Jack Knife Rep 10
English Text:
Phthalate Mec Weight Jack Knife Rep 10
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 789159.75121 Range of Values 2103 2103
. Missing 0 2103

WTSPH11 - Phthalate Mec Weight Jack Knife Rep 11

Variable Name:
WTSPH11
SAS Label:
Phthalate Mec Weight Jack Knife Rep 11
English Text:
Phthalate Mec Weight Jack Knife Rep 11
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 784645.39885 Range of Values 2103 2103
. Missing 0 2103

WTSPH12 - Phthalate Mec Weight Jack Knife Rep 12

Variable Name:
WTSPH12
SAS Label:
Phthalate Mec Weight Jack Knife Rep 12
English Text:
Phthalate Mec Weight Jack Knife Rep 12
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 780525.41317 Range of Values 2103 2103
. Missing 0 2103

WTSPH13 - Phthalate Mec Weight Jack Knife Rep 13

Variable Name:
WTSPH13
SAS Label:
Phthalate Mec Weight Jack Knife Rep 13
English Text:
Phthalate Mec Weight Jack Knife Rep 13
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 774699.59583 Range of Values 2103 2103
. Missing 0 2103

WTSPH14 - Phthalate Mec Weight Jack Knife Rep 14

Variable Name:
WTSPH14
SAS Label:
Phthalate Mec Weight Jack Knife Rep 14
English Text:
Phthalate Mec Weight Jack Knife Rep 14
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 800794.03906 Range of Values 2103 2103
. Missing 0 2103

WTSPH15 - Phthalate Mec Weight Jack Knife Rep 15

Variable Name:
WTSPH15
SAS Label:
Phthalate Mec Weight Jack Knife Rep 15
English Text:
Phthalate Mec Weight Jack Knife Rep 15
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 800067.91928 Range of Values 2103 2103
. Missing 0 2103

WTSPH16 - Phthalate Mec Weight Jack Knife Rep 16

Variable Name:
WTSPH16
SAS Label:
Phthalate Mec Weight Jack Knife Rep 16
English Text:
Phthalate Mec Weight Jack Knife Rep 16
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 771559.15812 Range of Values 2103 2103
. Missing 0 2103

WTSPH17 - Phthalate Mec Weight Jack Knife Rep 17

Variable Name:
WTSPH17
SAS Label:
Phthalate Mec Weight Jack Knife Rep 17
English Text:
Phthalate Mec Weight Jack Knife Rep 17
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 770860.4819 Range of Values 2103 2103
. Missing 0 2103

WTSPH18 - Phthalate Mec Weight Jack Knife Rep 18

Variable Name:
WTSPH18
SAS Label:
Phthalate Mec Weight Jack Knife Rep 18
English Text:
Phthalate Mec Weight Jack Knife Rep 18
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 778875.00902 Range of Values 2103 2103
. Missing 0 2103

WTSPH19 - Phthalate Mec Weight Jack Knife Rep 19

Variable Name:
WTSPH19
SAS Label:
Phthalate Mec Weight Jack Knife Rep 19
English Text:
Phthalate Mec Weight Jack Knife Rep 19
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 806797.8028 Range of Values 2103 2103
. Missing 0 2103

WTSPH20 - Phthalate Mec Weight Jack Knife Rep 20

Variable Name:
WTSPH20
SAS Label:
Phthalate Mec Weight Jack Knife Rep 20
English Text:
Phthalate Mec Weight Jack Knife Rep 20
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 785428.99916 Range of Values 2103 2103
. Missing 0 2103

WTSPH21 - Phthalate Mec Weight Jack Knife Rep 21

Variable Name:
WTSPH21
SAS Label:
Phthalate Mec Weight Jack Knife Rep 21
English Text:
Phthalate Mec Weight Jack Knife Rep 21
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 790952.9526 Range of Values 2103 2103
. Missing 0 2103

WTSPH22 - Phthalate Mec Weight Jack Knife Rep 22

Variable Name:
WTSPH22
SAS Label:
Phthalate Mec Weight Jack Knife Rep 22
English Text:
Phthalate Mec Weight Jack Knife Rep 22
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 784232.96861 Range of Values 2103 2103
. Missing 0 2103

WTSPH23 - Phthalate Mec Weight Jack Knife Rep 23

Variable Name:
WTSPH23
SAS Label:
Phthalate Mec Weight Jack Knife Rep 23
English Text:
Phthalate Mec Weight Jack Knife Rep 23
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 777601.80666 Range of Values 2103 2103
. Missing 0 2103

WTSPH24 - Phthalate Mec Weight Jack Knife Rep 24

Variable Name:
WTSPH24
SAS Label:
Phthalate Mec Weight Jack Knife Rep 24
English Text:
Phthalate Mec Weight Jack Knife Rep 24
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 784675.43003 Range of Values 2103 2103
. Missing 0 2103

WTSPH25 - Phthalate Mec Weight Jack Knife Rep 25

Variable Name:
WTSPH25
SAS Label:
Phthalate Mec Weight Jack Knife Rep 25
English Text:
Phthalate Mec Weight Jack Knife Rep 25
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 784085.31241 Range of Values 2103 2103
. Missing 0 2103

WTSPH26 - Phthalate Mec Weight Jack Knife Rep 26

Variable Name:
WTSPH26
SAS Label:
Phthalate Mec Weight Jack Knife Rep 26
English Text:
Phthalate Mec Weight Jack Knife Rep 26
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 777322.16598 Range of Values 2103 2103
. Missing 0 2103

WTSPH27 - Phthalate Mec Weight Jack Knife Rep 27

Variable Name:
WTSPH27
SAS Label:
Phthalate Mec Weight Jack Knife Rep 27
English Text:
Phthalate Mec Weight Jack Knife Rep 27
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 795953.93857 Range of Values 2103 2103
. Missing 0 2103

WTSPH28 - Phthalate Mec Weight Jack Knife Rep 28

Variable Name:
WTSPH28
SAS Label:
Phthalate Mec Weight Jack Knife Rep 28
English Text:
Phthalate Mec Weight Jack Knife Rep 28
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 800311.10032 Range of Values 2103 2103
. Missing 0 2103

WTSPH29 - Phthalate Mec Weight Jack Knife Rep 29

Variable Name:
WTSPH29
SAS Label:
Phthalate Mec Weight Jack Knife Rep 29
English Text:
Phthalate Mec Weight Jack Knife Rep 29
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 789325.00184 Range of Values 2103 2103
. Missing 0 2103

WTSPH30 - Phthalate Mec Weight Jack Knife Rep 30

Variable Name:
WTSPH30
SAS Label:
Phthalate Mec Weight Jack Knife Rep 30
English Text:
Phthalate Mec Weight Jack Knife Rep 30
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 806226.47957 Range of Values 2103 2103
. Missing 0 2103

WTSPH31 - Phthalate Mec Weight Jack Knife Rep 31

Variable Name:
WTSPH31
SAS Label:
Phthalate Mec Weight Jack Knife Rep 31
English Text:
Phthalate Mec Weight Jack Knife Rep 31
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 788890.82816 Range of Values 2103 2103
. Missing 0 2103

WTSPH32 - Phthalate Mec Weight Jack Knife Rep 32

Variable Name:
WTSPH32
SAS Label:
Phthalate Mec Weight Jack Knife Rep 32
English Text:
Phthalate Mec Weight Jack Knife Rep 32
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 752108.96539 Range of Values 2103 2103
. Missing 0 2103

WTSPH33 - Phthalate Mec Weight Jack Knife Rep 33

Variable Name:
WTSPH33
SAS Label:
Phthalate Mec Weight Jack Knife Rep 33
English Text:
Phthalate Mec Weight Jack Knife Rep 33
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 778810.00493 Range of Values 2103 2103
. Missing 0 2103

WTSPH34 - Phthalate Mec Weight Jack Knife Rep 34

Variable Name:
WTSPH34
SAS Label:
Phthalate Mec Weight Jack Knife Rep 34
English Text:
Phthalate Mec Weight Jack Knife Rep 34
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 784645.21465 Range of Values 2103 2103
. Missing 0 2103

WTSPH35 - Phthalate Mec Weight Jack Knife Rep 35

Variable Name:
WTSPH35
SAS Label:
Phthalate Mec Weight Jack Knife Rep 35
English Text:
Phthalate Mec Weight Jack Knife Rep 35
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 742569.15561 Range of Values 2103 2103
. Missing 0 2103

WTSPH36 - Phthalate Mec Weight Jack Knife Rep 36

Variable Name:
WTSPH36
SAS Label:
Phthalate Mec Weight Jack Knife Rep 36
English Text:
Phthalate Mec Weight Jack Knife Rep 36
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 779052.74392 Range of Values 2103 2103
. Missing 0 2103

WTSPH37 - Phthalate Mec Weight Jack Knife Rep 37

Variable Name:
WTSPH37
SAS Label:
Phthalate Mec Weight Jack Knife Rep 37
English Text:
Phthalate Mec Weight Jack Knife Rep 37
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 785043.84416 Range of Values 2103 2103
. Missing 0 2103

WTSPH38 - Phthalate Mec Weight Jack Knife Rep 38

Variable Name:
WTSPH38
SAS Label:
Phthalate Mec Weight Jack Knife Rep 38
English Text:
Phthalate Mec Weight Jack Knife Rep 38
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 813853.13128 Range of Values 2103 2103
. Missing 0 2103

WTSPH39 - Phthalate Mec Weight Jack Knife Rep 39

Variable Name:
WTSPH39
SAS Label:
Phthalate Mec Weight Jack Knife Rep 39
English Text:
Phthalate Mec Weight Jack Knife Rep 39
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 787513.41575 Range of Values 2103 2103
. Missing 0 2103

WTSPH40 - Phthalate Mec Weight Jack Knife Rep 40

Variable Name:
WTSPH40
SAS Label:
Phthalate Mec Weight Jack Knife Rep 40
English Text:
Phthalate Mec Weight Jack Knife Rep 40
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 787966.00414 Range of Values 2103 2103
. Missing 0 2103

WTSPH41 - Phthalate Mec Weight Jack Knife Rep 41

Variable Name:
WTSPH41
SAS Label:
Phthalate Mec Weight Jack Knife Rep 41
English Text:
Phthalate Mec Weight Jack Knife Rep 41
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 811402.56065 Range of Values 2103 2103
. Missing 0 2103

WTSPH42 - Phthalate Mec Weight Jack Knife Rep 42

Variable Name:
WTSPH42
SAS Label:
Phthalate Mec Weight Jack Knife Rep 42
English Text:
Phthalate Mec Weight Jack Knife Rep 42
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 785193.45114 Range of Values 2103 2103
. Missing 0 2103

WTSPH43 - Phthalate Mec Weight Jack Knife Rep 43

Variable Name:
WTSPH43
SAS Label:
Phthalate Mec Weight Jack Knife Rep 43
English Text:
Phthalate Mec Weight Jack Knife Rep 43
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 789336.29035 Range of Values 2103 2103
. Missing 0 2103

WTSPH44 - Phthalate Mec Weight Jack Knife Rep 44

Variable Name:
WTSPH44
SAS Label:
Phthalate Mec Weight Jack Knife Rep 44
English Text:
Phthalate Mec Weight Jack Knife Rep 44
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 786131.31634 Range of Values 2103 2103
. Missing 0 2103

WTSPH45 - Phthalate Mec Weight Jack Knife Rep 45

Variable Name:
WTSPH45
SAS Label:
Phthalate Mec Weight Jack Knife Rep 45
English Text:
Phthalate Mec Weight Jack Knife Rep 45
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 717399.16182 Range of Values 2103 2103
. Missing 0 2103

WTSPH46 - Phthalate Mec Weight Jack Knife Rep 46

Variable Name:
WTSPH46
SAS Label:
Phthalate Mec Weight Jack Knife Rep 46
English Text:
Phthalate Mec Weight Jack Knife Rep 46
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 803502.12242 Range of Values 2103 2103
. Missing 0 2103

WTSPH47 - Phthalate Mec Weight Jack Knife Rep 47

Variable Name:
WTSPH47
SAS Label:
Phthalate Mec Weight Jack Knife Rep 47
English Text:
Phthalate Mec Weight Jack Knife Rep 47
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 748407.58193 Range of Values 2103 2103
. Missing 0 2103

WTSPH48 - Phthalate Mec Weight Jack Knife Rep 48

Variable Name:
WTSPH48
SAS Label:
Phthalate Mec Weight Jack Knife Rep 48
English Text:
Phthalate Mec Weight Jack Knife Rep 48
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 785023.73178 Range of Values 2103 2103
. Missing 0 2103

WTSPH49 - Phthalate Mec Weight Jack Knife Rep 49

Variable Name:
WTSPH49
SAS Label:
Phthalate Mec Weight Jack Knife Rep 49
English Text:
Phthalate Mec Weight Jack Knife Rep 49
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 780791.20822 Range of Values 2103 2103
. Missing 0 2103

WTSPH50 - Phthalate Mec Weight Jack Knife Rep 50

Variable Name:
WTSPH50
SAS Label:
Phthalate Mec Weight Jack Knife Rep 50
English Text:
Phthalate Mec Weight Jack Knife Rep 50
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 775462.40387 Range of Values 2103 2103
. Missing 0 2103

WTSPH51 - Phthalate Mec Weight Jack Knife Rep 51

Variable Name:
WTSPH51
SAS Label:
Phthalate Mec Weight Jack Knife Rep 51
English Text:
Phthalate Mec Weight Jack Knife Rep 51
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 771051.13226 Range of Values 2103 2103
. Missing 0 2103

WTSPH52 - Phthalate Mec Weight Jack Knife Rep 52

Variable Name:
WTSPH52
SAS Label:
Phthalate Mec Weight Jack Knife Rep 52
English Text:
Phthalate Mec Weight Jack Knife Rep 52
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 783993.68521 Range of Values 2103 2103
. Missing 0 2103