Page 14 - Volume 3, Issue 1, January 2010

Operator exposure levels and evaluation of different coverall performance

13

specificity and limits of detection and quan-

tification. The limit of quantification (LOQ)

for the method corresponded to the lowest

fortification level giving acceptable recovery

(70-120%). Thus the LOQ was 10 μg for the

outer dosimeters and caps, 1 μg for inner do-

simeters and cotton gloves, 50 μg for nitrile

gloves and 0.1 μg for XAD tubes. The meth-

od LODs was 1/3 of the respective LOQs.

The fortification rates included five repli-

cates at LOQ and five replicates at 10xLOQ

levels for each dosimeter type, respective-

ly. The obtained results met the method val-

idation criteria. The accuracy assessment

was based on the recovery values obtained

from matrices fortified with certified analyt-

ical standards of known purity. These recov-

ery values ranged between 79 and 98% and

the corresponding RSDs were <4.2%. The

above data fulfilled the generally accepted

requirements for residue analytical meth-

Table 2.

Chromatography parameters.

Gas Chromatograph Agilent 6890N

Auto sampler

Gerstel MPS2-twister

Inlet

Split/Splitless injector

(splitless mode)

Detector

ECD

Column

HP-5 MS Agilent

(PN 19091S-433),

length 30m, ID 0.25mm,

film thick. 0.25 μm

Temperatures:

Inlet

Detector

Column

210°C

300°C

70°C, 1 min isothermal

70°C

280°C, 35°C/min, 2

min isothermal

Carrier gas: Helium 1.7 ml/min

Make up gas: Nitrogen 25 ml/min

Retention Times (Rt)

Pendimethaline 7.038 min

Iprodione 7.688 min

Table 3.

Operator exposure results to active substance (a.s.) of iprodione (mg a.s./kg a.s. ap-

plied).

Dosimeters

Exposure (mg a.s. /kg a.s. applied)

Protective Coverall Type A (Hydrofoil®) Protective Coverall Type B (Cotton)

A1 A2 A3 A4 A5 B1 B2 B3 B4 B5

Inner shirt

1.62 17.29 8.83 3.30 2.01 52.87 19.76 14.86 97.28 13.77

Inner pants

5.93 2.90 2.37 1.41 0.52 5.22 2.01 15.44 1.59 65.66

Actual Dermal Exposure (ADE)

(Inner coverall)

7.56 20.19 11.20 4.71 2.53 58.09 21.77 30.30 98.86 79.43

Outer jacket

622 983 168 153 126 526 1112 635 957 514

Outer pants

1961 1278 309 83 115 1974 871 896 1301 1368

Outer coverall

2582 2261 477 236 241 2499 1983 1532 2258 1883

Potential Dermal Exposure (PDE)

(Inner + Outer coverall)

2590 2281 489 240 243 2557 2005 1562 2357 1962

Inner gloves

0.230 2.883 0.808 0.378 0.433 0.196 0.349 0.373 3.803 0.873

Outer gloves

38.764 24.034 16.105 9.555 8.294 3.906 9.332 13.830 5.839 5.844

Head exposure

1

103.2 212.8 19.4 36.7 20.5 4.26 21.38 12.11 10.58 1.68

PDE + Head + Hand exposure 2732 2521 525 287 273 2566 2036 1588 2377 1971

Inhalation exposure

2

2.90 2.75 0.75 0.89 0.58 0.90 0.76 0.55 0.48 0.68

1

The values given for the head exposure derive from the residues (ml spray solution/h) found on operator’s cap

multiplied by a factor of 2.

2

The values given for inhalation exposure derive from the residues found on operator’s air sampler tube multiplied

by a factor of 29/2 (given that the human inhalation rate is 29 l/min, the air sampler’s pump flow rate was 2 l/min

and the net duration of the operator’s pump working was the same with the net duration of the application).