TITLE:
The effects of ultrasonic irradiation in combination with ozone on the reduction of residual ethion of tangerine (Citrus reticulata Blanco cv. Sai Nam Pung) fruit after harvest
AUTHORS:
Kanda Whangchai, Satit Phiyanalinmat, Jamnong Uthaibutra, Sarunya Pengphol, Nakao Nomura
KEYWORDS:
Tangerine; Ethion; Pesticide Residue; Ozone; Ultrasonic Irradiation
JOURNAL NAME:
Agricultural Sciences,
Vol.4 No.5B,
July
12,
2013
ABSTRACT: Ethion residue removal
efficiency using individual and combined effects of ultrasonication (US),
ozonation (O3), ultrasonication and ozonation (US/O3) was
investigated. A 1 mg·L-1 standard ethion was subjected to an ultrasonic irradiation (3W input power)
device with different frequencies of 108, 400, 700, 1000 kHz, and to an ozone
with a concentration of 200 mg· mL-1 with various exposure times
(0, 15, 30, 45 and 60 minutes). Reduction of residual ethion was determined by
gas chromatography with flame photometric detection (GC-FPD). It was found that
1000 kHz ultrasonic irradiation for 60 minutes was the most effective treatment
for reducing ethion concentration. Additionally, ozone could reduce the
concentration of standard ethion after 60 minutes of exposure. Ultrasonic irradiation
in combination with ozone had a synergistic effect in reducing standard ethion
concentration, with the highest rate occurring within the first 15 minutes.
Ethion concentration was reduced to 75.43% after ultrasonic irradiation at 1000 kHz and ozone exposure for 60 minutes.
The effectiveness of the combined scheme for reducing of ethion residues
on tangerine was also determined by GC-FPD. The ethion residue on fresh
tangerines after ultrasonic irradiation and ozone washing was reduced by 73.03%
after 60 minutes. The present study demonstrates that ultrasonic irradiation
and ozone exposure could be used to reduce
ethion residues in treated tangerine in order to meet the Standards for
Pesticide Residue Limits.