This presentation will be available to view as a discussion poster at the 7th International Conference on the Science of Exposure Assessment - X2012. It will be presented on 03 July 2012 from 13.45 – 15.45 followed by a chaired discussion of all posters in this session on Health Effects and Biological Monitoring. Appointments with the authors are available to book at https://x2012discussionposters.acuityscheduling.com

1. Simultaneous determination of urinary pyrethroid
insecticide metabolites in disposable diaper samples
Jun Ueyama1, Shun Saito1, Takaaki Kondo1, Isao Saito2,
Masahiro Gotoh3, Kunihiko Nakai4, Michihiro Kamijima5
1Department of Pathophysiological Laboratory Sciences, Nagoya University Graduate School of Medicine, Nagoya, Japan
2Food Safety and Quality Research Center, Tokai COOP Federation, Aichi, Japan
3Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya, Japan
4Department of Environmental Health Sciences, Tohoku University Graduate School of Medicine, Sendai, Japan
5Department of Occupational and Environmental Health, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
Abstract
□Urine sample has been frequently used for biomonitoring samples because of simple
collection method. It is difficult to collect urine samples from young children who can not
control their urination even using a urine collection bags.
□The aim of this study was to develop a simple and innovative method for the detection and
quantitation of urinary pyrethroid (PYR) metabolites in disposable diaper samples using
GC/MS analysis.
□PYR metabolites in the absorber of disposable diapers were extracted with 5 ml acetone in
manner of solid phase extraction.
□The limits of detection (LOD) were approximately 0.17 μ g/l for CDCA and 0.03 μg/l for 3-
PBA in 2 ml urine extracted from disposable diapers with good precision and accuracy.
□This measurement method may facilitate further studies of risk assessment of PYR
exposure among young children.

2. Introduction
>>The effects of chemical exposure on children’s health
have been drawing a broad attention around the world.
Urine sample has been frequently used for
biomonitoring samples because of simple collection
method. It is difficult to collect urine samples from
young children who can not control their urination even
using a urine collection bag (Fig. 1). For some infants who
undergo urine collection, the adhesive on the collection
bag might be stimulant enough to elicit skin rashes.
>>Among the classes of widely recognized insecticides, Fig. 1. Urine collection bags for infants.
PYR have today become the most frequently applied one
for indoor or domestic usage. There is little information
about the actual PYR exposure amounts and source in
diapered children.
>> The aim of this study was to develop a simple and
innovative method for the detection and quantitation of
urinary pyrethroid (PYR) metabolites trans-
chrysanthemumdicarboxylic acid (CDCA) and 3-
phenoxybenzoic acid (3-PBA)in disposable diaper Fig. 2. Disposable diapers.
samples.

3. Method
Top sheet
Hip Urine absorber
polyacrylate polymers Dry up with gentle nitrogen
and flocculent pulp
Water proof sheet
stream at 45C until
Typical cross section view of diapers approximately 1.5 ml
solution remained in the
tube
Remove about 1.5 gram of
wet absorber of diaper into
SPE tubes and measure the Fill distilled water to a
wet weight volume of 2 ml
Extract with 5 ml of acetone This sample was applied for previous
at flow rate 1.0 ml/min reported method for determination
of PYR metabolite in urine with
After extraction, dry up SPE tube slightly modifications (Leng et al.,
including absorber using evaporator for 1 2005).
hour and then measure the dry weight
Amount of urine in absorber was Fig. 3. Analytical procedure for
represented by weight margin of wet urinary PYR metabolites in disposable
and dry absorber diaper.

4. Result & Discussion
(A)
25
CDCA
150
3-PBA Fig. 4. Comparison of CDCA and
3-PBA concentration in urine
20
p < 0.01 p < 0.01
obtained from pest control
diaper method (g/L)
diaper method (g/L)
3-PBA measured by
CDCA measured by
r = 0.994 100 r = 0.993 operators (A) and general
15
population (B) using diaper
10
method (X-axis) and direct
50 method (Y-axis). Direct method
5 mean the determination
method of urinary PYR
0 0
0 5 10 15 20 25 0 50 100 150 metabolites from urine without
CDCA measured by direct method (g/L) 3-PBA measured by direct method (g/L) diapers. This data demonstrated
(B) CDCA 3-PBA that the utility of diaper method
3 10
for the measurement of wide-
2.5
p < 0.01 8 p < 0.01 ranging concentrations of PYR
diaper method (g/L)
diaper method (g/L)
3-PBA measured by
CDCA measured by
2
r = 0.880 r = 0.989 metabolite in urine collected
6 from various persons with
1.5
accuracy, precision and
4
1 sensitivity free of influence
0.5
2 from various urine matrixes.
0 0
0 0.5 1 1.5 2 2.5 3 0 2 4 6 8 10
CDCA measured by direct method (g/L) 3-PBA measured by direct method (g/L)
Abbreviation: r, spearman rank correlation coefficient.

5. Result & Discussion
Table 1. Accuracy, precision, LOD and LOQ of analytical precedure.
Pooled urine spiked concentration (µg/L)
These values were
n
CDCA 3-PBA CDCA 3-PBA approximately same
Within-run compared with the direct
Precision (%RSD) 5 0.4 13.8 methods which measured
5 0.5 0.9 8.7 9.9
5 2.0 2.4 3.6 5.3 urine that was not absorbed
5 20.0 20.4 5.4 5.2 diapers expect for LOD for
Absolute recovery 4 0.4 95.9
from urine absorber (%) 5 0.5 0.9 50.0 118.1 CDCA (Leng et al., 2005). LOD
5 2.0 2.4 73.9 97.4 for CDCA level was about
5 20.0 20.4 86.8 90.3
Between-run three times higher than direct
Precision (%RSD) 5 0.4 9.4 method ones.
5 0.5 0.9 8.1 11.7
5 2.0 2.4 4.2 4.6 This measurement method
5 20.0 20.4 5.6 3.7
R2 of calibration line
may contribute to
0.5-20 µg/L of urine 0.999 0.997 development for the study of
LOD (µg/L) (signal-to-noise ratio = 3) 0.17 0.03
LOQ (µg/L) (signal-to-noise ratio = 10) 0.55 0.09 the risk assessment of PYR
Abbreviations: n, number of observations; RSD, relative standard deviation; LOD, limit of exposure among young
detection; LOQ, limit of quantitation. children.