Table of Contents

Component Description

Exposure to volatile organic compounds (VOCs) is ubiquitous. Chronic exposure to extremely high levels of some VOCs can lead to cancer and neurocognitive dysfunction. Urinary metabolites of VOCs can be detectable in urine for a longer period of time than the parent VOCs can be detected in blood.

Nearly 200 air toxicants have been associated with adverse health effects in occupational studies or laboratory studies, but have not been monitored in general population groups. Information on levels of exposure to these compounds, as measured by their metabolite levels in urine, is essential to determine the need for regulatory mechanisms to reduce the levels of hazardous air pollutants to which the general population is exposed.

Eligible Sample

Examined participants aged 18 years and older from a one-third subsample were eligible. Additionally, to oversample adult smokers, those participants aged 18 years and older, not in the regular one-third subsample, who smoked at least 100 cigarettes in their entire lifetime (SMQ020=1) and now smoke cigarettes every day (SMQ040=1), were also included in this special subsample.

Description of Laboratory Methodology

This method is a quantitative procedure for the measurement of VOC metabolites in human urine using ultra performance liquid chromatography coupled with electrospray tandem mass spectrometry (UPLC-ESI/MSMS) as described by Alwis et al (2012). Chromatographic separation is achieved using an Acquity UPLC® HSS T3 (Part no. 186003540, 1.8 µm x 2.1 mm x 150 mm, Waters Inc.) column with 15 mM ammonium acetate and acetonitrile as the mobile phases. The eluent from the column is ionized using an electrospray interface to generate and transmit negative ions into the mass spectrometer. Comparison of relative response factors (ratio of native analyte to stable isotope labeled internal standard) with known standard concentrations yields individual analyte concentrations.

Refer to the Laboratory Method Files section for a detailed description of the laboratory methods used.

There were no changes to the lab method, lab equipment, or lab site for this component in the NHANES 2015-2016 cycle.

Laboratory Method Files

Urinary VOC Metabolites Laboratory Procedure Manual (November 2018)

Laboratory Quality Assurance and Monitoring

Urine specimens are processed, stored, and shipped to the Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta GA for analysis.

Detailed instructions on specimen collection and processing are discussed in the NHANES Laboratory Procedures Manual (LPM). Vials are stored under appropriate frozen (–20°C) conditions until they are shipped to National Center for Environmental Health for testing.

The NHANES QA/QC protocols meet the 1988 Clinical Laboratory Improvement Act mandates. Detailed QA/QC instructions are discussed in the NHANES LPM.

Mobile Examination Centers (MECs)

Laboratory team performance is monitored using several techniques. NCHS and contract consultants use a structured competency assessment evaluation during visits to evaluate both the quality of the laboratory work and the quality-control procedures. Each laboratory staff member is observed for equipment operation, specimen collection and preparation; testing procedures and constructive feedback are given to each staff member. Formal retraining sessions are conducted annually to ensure that required skill levels were maintained.

Analytical Laboratories

NHANES uses several methods to monitor the quality of the analyses performed by the contract laboratories. In the MEC, these methods include performing blind split samples collected during “dry run” sessions. In addition, contract laboratories randomly perform repeat testing on 2% of all specimens.

NCHS developed and distributed a quality control protocol for all CDC and contract laboratories, which outlined the use of Westgard rules (Westgard, et al. 1981) when running NHANES specimens. Progress reports containing any problems encountered during shipping or receipt of specimens, summary statistics for each control pool, QC graphs, instrument calibration, reagents, and any special considerations are submitted to NCHS quarterly. The reports are reviewed for trends or shifts in the data. The laboratories are required to explain any identified areas of concern.

All QC procedures recommended by the manufacturers were followed. Reported results for all assays meet the Division of Laboratory Sciences’ quality control and quality assurance performance criteria for accuracy and precision, similar to the Westgard rules (Caudill et al., 2008).

Data Processing and Editing

The data were reviewed. Incomplete data or improbable values were sent to the performing laboratory for confirmation.

Analytic Notes

Refer to the 2015-2016 Laboratory Data Overview for general information on NHANES laboratory data.

Subsample Weights

VOC metabolites in urine were measured in a special smoking subsample of participants aged 18 years and older. Special sample weights are required to analyze these data properly. Specific sample weights for this subsample are included in this data file and should be used when analyzing these data.

Demographic and Other Related Variables

The analysis of NHANES laboratory data must be conducted using the appropriate survey design and demographic variables. The NHANES 2015-2016 Demographics File contains demographic data, health indicators, and other related information collected during household interviews as well as the sample design variables. The recommended procedure for variance estimation requires use of stratum and PSU variables (SDMVSTRA and SDMVPSU, respectively) in the demographic data file.

This laboratory data file can be linked to the other NHANES data files using the unique survey participant identifier (i.e., SEQN).

Detection limits

The detection limits were constant for the analytes in the data set. Two variables are provided for each of these analytes. The variable named ending in “LC” (ex., URDAAMLC) indicates whether the result was below the limit of detection: the value “0” means that the result was at or above the limit of detection, “1” indicates that the result was below the limit of detection. For analytes with analytic results below the lower limit of detection (ex., URDAAMLC=1), an imputed fill value was placed in the analyte results field. This value is the lower limit of detection divided by the square root of 2 (LLOD/sqrt [2]). The other variable prefixed URX (ex., URXAAM) provides the analytic result for the analyte. All data are rounded to three significant figures or three decimal places, whichever is less precise.

The lower limit of detection (LLOD, in ng/mL) for urinary VOC metabolites:

VARIABLE NAME

SAS LABEL

LLOD

URXAAM

N-Acetyl-S-(2-carbamoylethyl)-L-cysteine (ng/mL)

2.20

URXAMC

N-Acetyl-S-(N-methylcarbamoyl)-L-cysteine (ng/mL)

6.26

URXATC

2-Aminothiazoline-4-carboxylic acid (ng/mL)

15.0

URXBMA

N-Acetyl-S-(benzyl)-L-cysteine (ng/mL)

0.500

URXBPM

N-Acetyl-S-(n-propyl)-L-cysteine (ng/mL)

1.20

URXCEM

N-Acetyl-S-(2-carboxyethyl)-L-cysteine (ng/mL)

6.96

URXCYHA

N-Acetyl-S-(1-cyano-2-hydroxyethyl)-L-cysteine (ng/mL)

2.60

URXCYM

N-Acetyl-S-(2-cyanoethyl)-L-cysteine (ng/mL)

0.500

URX1DC

N-Acetyl-S-(1,2-dichlorovinyl)-L-cysteine (ng/mL)

12.6

URX2DC

N-Acetyl-S-(2,2-dichlorovinyl)-L-cysteine (ng/mL)

13.9

URXDHB

N-Acetyl-S-(3,4-dihydroxybutyl)-L-cysteine (ng/mL)

5.25

URXDPM

N-Acetyl-S-(dimethylphenyl)-L-cysteine (ng/mL)

0.500

URXGAM

N-Acetyl-S-(2-carbamoyl-2-hydroxyethyl)-L-cysteine (ng/mL)

9.40

URXHEM

N-Acetyl-S-(2-hydroxyethyl)-L-cysteine (ng/mL)

0.791

URXHPM

N-Acetyl-S-(3-hydroxypropyl)-L-cysteine (ng/mL)

13.0

URXHP2

N-Acetyl-S-(2-hydroxypropyl)-L-cysteine (ng/mL)

5.30

URXIPM1

N-Acetyl-S-(2-hydroxy-3-methyl-3-butenyl)-L-cysteine +

N-Acetyl-S-(2-hydroxy-2-methyl-3-butenyl)-L-cysteine

1.43

URXIPM3

N-Acetyl- S- (4- hydroxy- 2- methyl- 2- butenyl)- L- cysteine (ng/mL)

1.20

URXMAD

Mandelic acid (ng/mL)

12.0

URX2MH

2-Methylhippuric acid (ng/mL)

5.00

URX34M

3- and 4-Methylhippuric acid (ng/mL)

8.00

URXMB1

N-Acetyl-S-(1-hydroxymethyl-2-propenyl)-L-cysteine (ng/mL)

0.700

URXMB2

N-Acetyl-S-(2-hydroxy-3-butenyl)-L-cysteine (ng/mL)

0.700

URXMB3

N-Acetyl-S-(4-hydroxy-2-butenyl)-L-cysteine (ng/mL)

0.600

URXPHE

N-Acetyl-S-(phenyl-2-hydroxyethyl)-L-cysteine (ng/mL)

0.700

URXPHG

Phenylglyoxylic acid (ng/mL)

12.0

URXPMA

N-Acetyl-S-(phenyl)-L-cysteine (ng/mL)

0.600

URXPMM

N-Acetyl-S-(3-hydroxypropyl-1-methyl)-L-cysteine (ng/mL)

3.00

URXTCV

N-Acetyl-S-(trichlorovinyl)-L-cysteine (ng/mL)

3.00

  

Please refer to the NHANES Analytic Guidelines and the on-line NHANES Tutorial for further details on the use of sample weights and other analytic issues.

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 18 YEARS - 150 YEARS

WTFSM - Two Year Smoking Weights

Variable Name:
WTFSM
SAS Label:
Two Year Smoking Weights
English Text:
Two Year Smoking Weights
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
5682.8332946 to 708016.13026 Range of Values 2389 2389
0 No Lab Result 73 2462
. Missing 0 2462

URX1DC - N-acel-S-(1,2-dichlorovinl)-L-cys(ng/mL)

Variable Name:
URX1DC
SAS Label:
N-acel-S-(1,2-dichlorovinl)-L-cys(ng/mL)
English Text:
N-acetyl-S-(1,2-dichlorovinyl)-L-cysteine (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
8.9 8.9 2261 2261
. Missing 201 2462

URD1DCLC - N-acel-S-(1,2-dichlorovinl)-L-cys comt

Variable Name:
URD1DCLC
SAS Label:
N-acel-S-(1,2-dichlorovinl)-L-cys comt
English Text:
N-acetyl-S-(1,2-dichlorovinyl)-L-cysteine comment code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 0 0
1 Below lower detection limit 2261 2261
. Missing 201 2462

URX2DC - N-acel-S-(2,2-dichlorvinyl)-L-cys(ng/mL)

Variable Name:
URX2DC
SAS Label:
N-acel-S-(2,2-dichlorvinyl)-L-cys(ng/mL)
English Text:
N-acetyl-S-(2,2-dichlorovinyl)-L-cysteine (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
9.8 9.8 2202 2202
. Missing 260 2462

URD2DCLC - N-acel-S-(2,2-dichlorvinyl)-L-cys comt

Variable Name:
URD2DCLC
SAS Label:
N-acel-S-(2,2-dichlorvinyl)-L-cys comt
English Text:
N-acetyl-S-(2,2-dichlorovinyl)-L-cysteine comment code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 0 0
1 Below lower detection limit 2202 2202
. Missing 260 2462

URX2MH - 2-methylhippuric acid (ng/mL)

Variable Name:
URX2MH
SAS Label:
2-methylhippuric acid (ng/mL)
English Text:
2-methylhippuric acid (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
3.54 to 10300 Range of Values 2356 2356
. Missing 106 2462

URD2MHLC - 2-methylhippuric acid comment code

Variable Name:
URD2MHLC
SAS Label:
2-methylhippuric acid comment code
English Text:
2-methylhippuric acid comment code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 2214 2214
1 Below lower detection limit 142 2356
. Missing 106 2462

URX34M - 3-methipurc acd & 4-methipurc acd(ng/mL)

Variable Name:
URX34M
SAS Label:
3-methipurc acd & 4-methipurc acd(ng/mL)
English Text:
3-methylhippuric acid & 4-methylhippuric acid(ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
5.66 to 33800 Range of Values 2356 2356
. Missing 106 2462

URD34MLC - 3-methipurc acd & 4-methipurc acid comt

Variable Name:
URD34MLC
SAS Label:
3-methipurc acd & 4-methipurc acid comt
English Text:
3-methylhippuric acid & 4-methylhippuric acid comment code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 2351 2351
1 Below lower detection limit 5 2356
. Missing 106 2462

URXAAM - N-ace-S-(2-carbamoylethyl)-L-cys(ng/mL)

Variable Name:
URXAAM
SAS Label:
N-ace-S-(2-carbamoylethyl)-L-cys(ng/mL)
English Text:
N-acetyl-S-(2-carbamoylethyl)-L-cysteine(ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1.56 to 2160 Range of Values 2356 2356
. Missing 106 2462

URDAAMLC - N-ace-S-(2-carbamoylethyl)-L-cys comt

Variable Name:
URDAAMLC
SAS Label:
N-ace-S-(2-carbamoylethyl)-L-cys comt
English Text:
N-acetyl-S-(2-carbamoylethyl)-L-cysteine comment code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 2354 2354
1 Below lower detection limit 2 2356
. Missing 106 2462

URXAMC - N-ace-S-(N-methlcarbamoyl)-L-cys(ng/mL)

Variable Name:
URXAMC
SAS Label:
N-ace-S-(N-methlcarbamoyl)-L-cys(ng/mL)
English Text:
N-acetyl-S-(N-methylcarbamoyl)-L-cysteine(ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
4.43 to 3350 Range of Values 2304 2304
. Missing 158 2462

URDAMCLC - N-ace-S-(N-methlcarbamoyl)-L-cys comt

Variable Name:
URDAMCLC
SAS Label:
N-ace-S-(N-methlcarbamoyl)-L-cys comt
English Text:
N-acetyl-S-(N-methylcarbamoyl)-L-cysteine comment code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 2300 2300
1 Below lower detection limit 4 2304
. Missing 158 2462

URXATC - 2-amnothiazolne-4-carbxylic acid(ng/mL)

Variable Name:
URXATC
SAS Label:
2-amnothiazolne-4-carbxylic acid(ng/mL)
English Text:
2-aminothiazoline-4-carboxylic acid(ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
10.6 to 2590 Range of Values 2356 2356
. Missing 106 2462

URDATCLC - 2-amnothiazolne-4-carbxylic acid comt

Variable Name:
URDATCLC
SAS Label:
2-amnothiazolne-4-carbxylic acid comt
English Text:
2-amnothiazolne-4-carbxylic acid comment code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 2276 2276
1 Below lower detection limit 80 2356
. Missing 106 2462

URXBMA - N-acetyl-S-(benzyl)-L-cysteine(ng/mL)

Variable Name:
URXBMA
SAS Label:
N-acetyl-S-(benzyl)-L-cysteine(ng/mL)
English Text:
N-acetyl-S-(benzyl)-L-cysteine(ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.354 to 1330 Range of Values 2355 2355
. Missing 107 2462

URDBMALC - N-acetyl-S-(benzyl)-L-cysteine comt

Variable Name:
URDBMALC
SAS Label:
N-acetyl-S-(benzyl)-L-cysteine comt
English Text:
N-acetyl-S-(benzyl)-L-cysteine comment code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 2349 2349
1 Below lower detection limit 6 2355
. Missing 107 2462

URXBPM - N-acetyl-S-(n-propyl)-L-cysteine(ng/mL)

Variable Name:
URXBPM
SAS Label:
N-acetyl-S-(n-propyl)-L-cysteine(ng/mL)
English Text:
N-acetyl-S-(n-propyl)-L-cysteine(ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.85 to 707 Range of Values 2302 2302
. Missing 160 2462

URDBPMLC - N-acetyl-S-(n-propyl)-L-cysteine comt

Variable Name:
URDBPMLC
SAS Label:
N-acetyl-S-(n-propyl)-L-cysteine comt
English Text:
N-acetyl-S-(n-propyl)-L-cysteine comment code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 1855 1855
1 Below lower detection limit 447 2302
. Missing 160 2462

URXCEM - N-acetyl-S-(2-carbxyethyl)-L-cys(ng/mL)

Variable Name:
URXCEM
SAS Label:
N-acetyl-S-(2-carbxyethyl)-L-cys(ng/mL)
English Text:
N-acetyl-S-(2-carboxyethyl)-L-cysteine(ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
4.92 to 3670 Range of Values 2356 2356
. Missing 106 2462

URDCEMLC - N-acetyl-S-(2-carbxyethyl)-L-cys comt

Variable Name:
URDCEMLC
SAS Label:
N-acetyl-S-(2-carbxyethyl)-L-cys comt
English Text:
N-acetyl-S- (2-carboxyethyl)-L-cysteine comment code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 2349 2349
1 Below lower detection limit 7 2356
. Missing 106 2462

URXCYHA - CYHA cysteine (ng/mL)

Variable Name:
URXCYHA
SAS Label:
CYHA cysteine (ng/mL)
English Text:
N-Acetyl-S-(1-cyano-2-hydroxyethyl)-L-cysteine (CYHA) (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1.84 to 510 Range of Values 2356 2356
. Missing 106 2462

URDCYALC - CYHA cysteine comment code

Variable Name:
URDCYALC
SAS Label:
CYHA cysteine comment code
English Text:
N-Acetyl-S-(1-cyano-2-hydroxyethyl)-L-cysteine (CYHA) comment code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 857 857
1 Below lower detection limit 1499 2356
. Missing 106 2462

URXCYM - N-acetyl-S-(2-cyanoethyl)-L-cyst(ng/mL)

Variable Name:
URXCYM
SAS Label:
N-acetyl-S-(2-cyanoethyl)-L-cyst(ng/mL)
English Text:
N-acetyl-S-(2-cyanoethyl)-L-cysteine(ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.354 to 2370 Range of Values 2356 2356
. Missing 106 2462

URDCYMLC - N-acetyl-S-(2-cyanoethyl)-L-cyst comt

Variable Name:
URDCYMLC
SAS Label:
N-acetyl-S-(2-cyanoethyl)-L-cyst comt
English Text:
N-acetyl-S-(2-cyanoethyl)-L-cysteine comment code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 2013 2013
1 Below lower detection limit 343 2356
. Missing 106 2462

URXDHB - N-ace-S-(3,4-dihidxybutl)-L-cys(ng/mL)

Variable Name:
URXDHB
SAS Label:
N-ace-S-(3,4-dihidxybutl)-L-cys(ng/mL)
English Text:
N-acetyl-S- (3,4-dihidroxybutyl)-L-cysteine(ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
19.7 to 4330 Range of Values 2116 2116
. Missing 346 2462

URDDHBLC - N-ace-S-(3,4-dihidxybutl)-L-cys comt

Variable Name:
URDDHBLC
SAS Label:
N-ace-S-(3,4-dihidxybutl)-L-cys comt
English Text:
N-acetyl-S- (3,4-dihidroxybutyl)-L-cysteine comment code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 2116 2116
1 Below lower detection limit 0 2116
. Missing 346 2462

URXDPM - N-ace-S-(dimethylphenyl)-L-cys(ng/mL)

Variable Name:
URXDPM
SAS Label:
N-ace-S-(dimethylphenyl)-L-cys(ng/mL)
English Text:
N-acetyl-S-(dimethylphenyl)-L-cysteine(ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.354 to 6.38 Range of Values 2356 2356
. Missing 106 2462

URDDPMLC - N-ace-S-(dimethylphenyl)-L-cys comt

Variable Name:
URDDPMLC
SAS Label:
N-ace-S-(dimethylphenyl)-L-cys comt
English Text:
N-acetyl-S-(dimethylphenyl)-L-cysteine comment code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 8 8
1 Below lower detection limit 2348 2356
. Missing 106 2462

URXGAM - N-ac-S-(2-carbmo-2-hydxel)-L-cys(ng/mL)

Variable Name:
URXGAM
SAS Label:
N-ac-S-(2-carbmo-2-hydxel)-L-cys(ng/mL)
English Text:
N-acetyl-S-(2-carbamoyl-2-hydroxyethyl)-L-cysteine(ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
6.65 to 169 Range of Values 2356 2356
. Missing 106 2462

URDGAMLC - N-ac-S-(2-carbmo-2-hydxel)-L-cys comt

Variable Name:
URDGAMLC
SAS Label:
N-ac-S-(2-carbmo-2-hydxel)-L-cys comt
English Text:
N-acetyl-S-(2-carbamoyl-2-hydroxyethyl)-L-cysteine comment code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 1158 1158
1 Below lower detection limit 1198 2356
. Missing 106 2462

URXHEM - N-ace-S-(2-hydroxyethyl)-L-cys(ng/mL)

Variable Name:
URXHEM
SAS Label:
N-ace-S-(2-hydroxyethyl)-L-cys(ng/mL)
English Text:
N-acetyl-S-(2-hydroxyethyl)-L-cysteine(ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.559 to 81.9 Range of Values 2356 2356
. Missing 106 2462

URDHEMLC - N-ace-S-(2-hydroxyethyl)-L-cys comt

Variable Name:
URDHEMLC
SAS Label:
N-ace-S-(2-hydroxyethyl)-L-cys comt
English Text:
N-acetyl-S-(2-hydroxyethyl)-L-cysteine comment code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 1339 1339
1 Below lower detection limit 1017 2356
. Missing 106 2462

URXHP2 - N-ace-S-(2-hydroxypropyl)-L-cys(ng/mL)

Variable Name:
URXHP2
SAS Label:
N-ace-S-(2-hydroxypropyl)-L-cys(ng/mL)
English Text:
N-acetyl-S- (2-hydroxypropyl)-L-cysteine(ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
3.75 to 9830 Range of Values 2356 2356
. Missing 106 2462

URDHP2LC - N-ace-S-(2-hydroxypropyl)-L-cys comt

Variable Name:
URDHP2LC
SAS Label:
N-ace-S-(2-hydroxypropyl)-L-cys comt
English Text:
N-acetyl-S- (2-hydroxypropyl)-L-cysteine comment code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 2269 2269
1 Below lower detection limit 87 2356
. Missing 106 2462

URXHPM - N-ace-S-(3-hydroxypropyl)-L-cys(ng/mL)

Variable Name:
URXHPM
SAS Label:
N-ace-S-(3-hydroxypropyl)-L-cys(ng/mL)
English Text:
N-acetyl-S- (3-hydroxypropyl)-L-cysteine(ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
9.2 to 12900 Range of Values 2211 2211
. Missing 251 2462

URDHPMLC - N-ace-S-(3-hydroxypropyl)-L-cys comt

Variable Name:
URDHPMLC
SAS Label:
N-ace-S-(3-hydroxypropyl)-L-cys comt
English Text:
N-acetyl-S- (3-hydroxypropyl)-L-cysteine comment code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 2209 2209
1 Below lower detection limit 2 2211
. Missing 251 2462

URXIPM1 - IPM1 cysteine (ng/mL)

Variable Name:
URXIPM1
SAS Label:
IPM1 cysteine (ng/mL)
English Text:
N-Acetyl-S-(2-hydroxy-3-methyl-3-butenyl)-L-cysteine + N-Acetyl-S-(2-hydroxy-2-methyl-3-butenyl)-L-cysteine (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1.01 to 250 Range of Values 2356 2356
. Missing 106 2462

URDPM1LC - IPM1 cysteine comment code

Variable Name:
URDPM1LC
SAS Label:
IPM1 cysteine comment code
English Text:
N-Acetyl-S-(2-hydroxy-3-methyl-3-butenyl)-L-cysteine + N-Acetyl-S-(2-hydroxy-2-methyl-3-butenyl)-L-cysteine comment code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 2050 2050
1 Below lower detection limit 306 2356
. Missing 106 2462

URXIPM3 - IPM3 cysteine (ng/mL)

Variable Name:
URXIPM3
SAS Label:
IPM3 cysteine (ng/mL)
English Text:
N-Acetyl-S-(4-hydroxy-2-methyl-2-butenyl)-L-cysteine (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.85 to 492 Range of Values 2356 2356
. Missing 106 2462

URDPM3LC - IPM3 cysteine comment code

Variable Name:
URDPM3LC
SAS Label:
IPM3 cysteine comment code
English Text:
N-Acetyl-S-(4-hydroxy-2-methyl-2-butenyl)-L-cysteine comment code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 2041 2041
1 Below lower detection limit 315 2356
. Missing 106 2462

URXMAD - Mandelic acid(ng/mL)

Variable Name:
URXMAD
SAS Label:
Mandelic acid(ng/mL)
English Text:
Mandelic acid(ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
8.5 to 4390 Range of Values 2350 2350
. Missing 112 2462

URDMADLC - Mandelic acid comment code

Variable Name:
URDMADLC
SAS Label:
Mandelic acid comment code
English Text:
Mandelic acid comment code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 2334 2334
1 Below lower detection limit 16 2350
. Missing 112 2462

URXMB1 - N-A-S-(1-hydrxmet)-2-Prpn)-L-cys(ng/mL)

Variable Name:
URXMB1
SAS Label:
N-A-S-(1-hydrxmet)-2-Prpn)-L-cys(ng/mL)
English Text:
N-acetyl-S-(1-hydroxymethyl)-2-Propenyl)-L-cysteine(ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.495 to 3.6 Range of Values 2340 2340
. Missing 122 2462

URDMB1LC - N-A-S-(1-hydrxmet)-2-Prpn)-L-cys comt

Variable Name:
URDMB1LC
SAS Label:
N-A-S-(1-hydrxmet)-2-Prpn)-L-cys comt
English Text:
N-acetyl-S-(1-hydroxymethyl)-2-Propenyl)-L-cysteine comment code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 39 39
1 Below lower detection limit 2301 2340
. Missing 122 2462

URXMB2 - N-Ac-S-(2-hydrxy-3-butenyl)-L-cys(ng/mL)

Variable Name:
URXMB2
SAS Label:
N-Ac-S-(2-hydrxy-3-butenyl)-L-cys(ng/mL)
English Text:
N-acetyl-S- (2-hydroxy-3-butenyl)-L-cysteine (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.495 to 94.9 Range of Values 2356 2356
. Missing 106 2462

URDMB2LC - N-Ac-S-(2-hydrxy-3-butenyl)-L-cys comt

Variable Name:
URDMB2LC
SAS Label:
N-Ac-S-(2-hydrxy-3-butenyl)-L-cys comt
English Text:
N-acetyl-S-(2-hydroxy-3-butenyl)-L-cysteine comment code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 581 581
1 Below lower detection limit 1775 2356
. Missing 106 2462

URXMB3 - N-A-S-(4-hydrxy-2-butenyl)-L-cys(ng/mL)

Variable Name:
URXMB3
SAS Label:
N-A-S-(4-hydrxy-2-butenyl)-L-cys(ng/mL)
English Text:
N-acetyl-S- (4-hydroxy-2-butenyl)-L-cysteine (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.424 to 407 Range of Values 2356 2356
. Missing 106 2462

URDMB3LC - N-A-S-(4-hydrxy-2-butenyl)-L-cys comt

Variable Name:
URDMB3LC
SAS Label:
N-A-S-(4-hydrxy-2-butenyl)-L-cys comt
English Text:
N-acetyl-S- (4-hydroxy-2-butenyl)-L-cysteine comment code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 2248 2248
1 Below lower detection limit 108 2356
. Missing 106 2462

URXPHE - N-ace-S-(phenl-2-hydxyetl)-L-cys(ng/mL)

Variable Name:
URXPHE
SAS Label:
N-ace-S-(phenl-2-hydxyetl)-L-cys(ng/mL)
English Text:
N-acetyl-S-(phenyl-2-hydroxyethyl)-L-cysteine(ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.495 to 107 Range of Values 2306 2306
. Missing 156 2462

URDPHELC - N-ace-S-(phenl-2-hydxyetl)-L-cys comt

Variable Name:
URDPHELC
SAS Label:
N-ace-S-(phenl-2-hydxyetl)-L-cys comt
English Text:
N-acetyl-S-(phenyl-2-hydroxyethyl)-L-cysteine comment code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 1370 1370
1 Below lower detection limit 936 2306
. Missing 156 2462

URXPHG - Phenylglyoxylic acid(ng/mL)

Variable Name:
URXPHG
SAS Label:
Phenylglyoxylic acid(ng/mL)
English Text:
Phenylglyoxylic acid(ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
8.5 to 5640 Range of Values 2353 2353
. Missing 109 2462

URDPHGLC - Phenylglyoxylic acid comment code

Variable Name:
URDPHGLC
SAS Label:
Phenylglyoxylic acid comment code
English Text:
Phenylglyoxylic acid comment code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 2341 2341
1 Below lower detection limit 12 2353
. Missing 109 2462

URXPMA - N-acetyl-S-(phenyl)-L-cysteine(ng/mL)

Variable Name:
URXPMA
SAS Label:
N-acetyl-S-(phenyl)-L-cysteine(ng/mL)
English Text:
N-acetyl-S-(phenyl)-L-cysteine(ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.424 to 28 Range of Values 2356 2356
. Missing 106 2462

URDPMALC - N-acetyl-S-(phenyl)-L-cysteine comt

Variable Name:
URDPMALC
SAS Label:
N-acetyl-S-(phenyl)-L-cysteine comt
English Text:
N-acetyl-S-(phenyl)-L-cysteine comment code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 1158 1158
1 Below lower detection limit 1198 2356
. Missing 106 2462

URXPMM - N-A-S-(3-hydrxprpl-1-metl)-L-cys(ng/mL)

Variable Name:
URXPMM
SAS Label:
N-A-S-(3-hydrxprpl-1-metl)-L-cys(ng/mL)
English Text:
N-acetyl-S-(3-hydroxypropyl-1-methyl)-L-cysteine(ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
18 to 30000 Range of Values 2356 2356
. Missing 106 2462

URDPMMLC - N-A-S-(3-hydrxprpl-1-metl)-L-cys comt

Variable Name:
URDPMMLC
SAS Label:
N-A-S-(3-hydrxprpl-1-metl)-L-cys comt
English Text:
N-acetyl-S-(3-hydroxypropyl-1-methyl)-L-cysteine comment code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 2356 2356
1 Below lower detection limit 0 2356
. Missing 106 2462

URXTCV - N-acetyl-S-(trichlorovinyl)-L-cys(ng/mL)

Variable Name:
URXTCV
SAS Label:
N-acetyl-S-(trichlorovinyl)-L-cys(ng/mL)
English Text:
N-acetyl-S-(trichlorovinyl)-L-cysteine(ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
2.12 2.12 2356 2356
. Missing 106 2462

URDTCVLC - N-acetyl-S-(trichlorovinyl)-L-cys comt

Variable Name:
URDTCVLC
SAS Label:
N-acetyl-S-(trichlorovinyl)-L-cys comt
English Text:
N-acetyl-S-(trichlorovinyl)-L-cysteine comment code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 0 0
1 Below lower detection limit 2356 2356
. Missing 106 2462