Orthophenylphenol and Phenylhydroquinone Residues in Citrus Fruit and Processed Citrus Products after Postharvest Fungicidal Treatments with Sodium Orthophenylphenate in California and Florida

Abstract

Sodium orthophenylphenate (SOPP) has been used extensively for >40 years to control postharvest diseases of citrus fruits. Studies of the metabolism of [(14)C]SOPP have identified orthophenylphenol (OPP) as the major metabolite with phenylhydroquinone (PHQ) as a minor metabolite. The whole-fruit tolerance in the United States for OPP is 10 ppm. This study was conducted to quantify terminal OPP and PHQ residues in whole Navel oranges, grapefruit, and lemons following SOPP applications at maximum application rates and following commercial application and fruit storage practices. OPP and PHQ residues also were determined in products processed from treated Navel oranges. OPP residues in lemons, Navel oranges, and grapefruit treated with SOPP using foamer wash and shipping wax applications remained below the 10 ppm tolerance, and PHQ residues were all < or =0.439 ppm. PHQ residues in whole fruit increased with time in commercial storage. OPP residues in all Navel orange matrices except oil remained relatively stable with time in commercial storage; residues in oil declined substantially while in storage.

Imazalil resistance in Penicillium digitatum and P. italicum causing citrus postharvest green and blue mould: Impact and options

“…comm.). Sodium ortho-phenyl-phenol (SOPP) has been in use for > 50 years (Johnson et al, 2001), but is not commonly used in South Africa, mostly due to the possible risk of phytotoxicity if not managed well. Resistance to SOPP has already been reported in the early 1960s (Harding, 1962).…”

Solid-phase spectrophosphorimetric determination of the pesticide o-phenylphenol in water and vegetables

“…The linear dynamic range was obtained from the expression 0.1(L u /L i ) where L u is the upper limit of linearity of the method and L i is the lower limit, and the linear range of application of the method was 0.5-4.0 mg kg -1 . This range is suitable for the determination of OPP in fruits and vegetables in the United States where the whole-fruit tolerance for OPP is 10 mg kg -1 [18], and, additionally, it is in accordance with the FAO/WHO [19], which stipulates an acceptable daily intake of OPP of 0.02 mg kg -1 day -1 . If we suppose that the weight of a person can fluctuate between 20 kg (children) and 80 kg (adult), the ingested amount of OPP can range between 0.4 and 1.6 mg day -1 .…”

Sodium dodecyl sulfate sensitized electrochemical method for subnanomole level determination of ortho-phenylphenol at a novel disposable electrode

“…Several methods have been reported to detect OPP residues in citrus fruit. Such methods include liquid chromatography (LC) with different detections [5,[7][8][9][10][11][12][13], gas chromatography (GC) (sometimes after derivatization) with different detections [14][15][16][17][18] and spectrophotometry [19,20]. However, most of the published methods require a long and laborious sample preparation as well as large sample amounts due to their low sensitivity and selectivity and all the mentioned instrumentation was fairly expensive.…”