A simple and reproducible testing method for dialkyl phthalate migration from polyvinyl chloride products into saliva simulant.
We describe a method of mechanical agitation to determine rates of dialkyl phthalate migration from polyvinyl chloride (PVC) products into saliva simulant. The method consists of rotary shaking of a sample with 30 mL of saliva simulant (pH 7.0) at 35 degrees C in a 50 mL glass tube at 300 rpm for 15 min, then measuring the amount of dialkyl phthalate in the saliva simulant by HPLC with a UV detector. The migration rates of diisononyl phthalate (DINP), di-2-ethylhexyl phthalate (DEHP) and di-n-butyl phthalate (DBP) from PVC plates containing about 45% (w/w) plasticizer (molded in our laboratory) were identical. However, the migration rates from molded plates containing 13% (w/w) DBP were almost double those of DINP and DEHP at the same ratios. In addition, the amounts of DINP that migrated in vitro after rotary shaking for 15 min were equivalent to those in vivo determined in saliva from volunteers who chewed plates for 60 min. The migration rates of dialkyl phthalates from 11 commercially available toys ranged from 15.6 to 85.2 micrograms/cm2/h [relative standard deviation (RSD), 3 to 12%].
Niino
Tatsuhiro
T
Tokyo Kenbikyo-in Foundation, Center of Food & Environmental Sciences: 44-1, Nihonbashi, Hakozaki-cho, Chuo-ku, Tokyo 103-0015, Japan.
Asakura
Takayuki
T
Ishibashi
Tohru
T
Itoh
Takeshi
T
Sakai
Senzo
S
Ishiwata
Hajimu
H
Yamada
Takashi
T
Onodera
Sukeo
S
D002851:Chromatography, High Pressure Liquid; D003993:Dibutyl Phthalate / Q000032:analysis; D004051:Diethylhexyl Phthalate / Q000032:analysis; D008954:Models, Biological; D010795:Phthalic Acids / Q000032:analysis*; D010988:Play and Playthings; D011143:Polyvinyl Chloride / Q000032:analysis*; D012463:Saliva / Q000737:chemistry*
D010795:Phthalic Acids; C471688:diisooctyl phthalate; D003993:Dibutyl Phthalate; D011143:Polyvinyl Chloride; D004051:Diethylhexyl Phthalate; C049098:diallyl phthalate