The relationship between cooking procedure and pesticide species on pesticide residues in raw crops was examined using pesticide-containing commercial green tea leaves, spinach, strawberries, oranges, and grapefruit. The residual organophosphorus pesticides in green tea leaves and in crops were decreased on leaching or cooking, and the rate of decrease was closely related to the octanol-water partition coefficient. The regression expression log(L r ) ) 2.25 -0.312 log K ow , r ) 0.923, where L r is the translocated pesticide concentration in drawn tea (%) and K ow is the partition coefficient (octanol/water) of the pesticide, was shown from the relationship between the amount of organophosphorus pesticides in the tea leaves and the amount dissolved into the brewed tea. On the other hand, the decrease of organophosphorus pesticide residues in spinach after 5 min of boiling or in an orange after cooking and the pesticide K ow fit the equation log(P r ) ) 1.59 + 0.06 log K ow , r ) 0.991, in boiled spinach, log(P r ) ) 0.51 + 0.40 log K ow , r ) 0.978, in orange marmalade, and log(P r ) ) -5.28 + 2.12 log K ow , r ) 0.946, in orange candied peel, where P r is the percent of pesticide remaining in the fresh state. The pesticide remained in the processed food according to the K ow expression. The relationship was similar for the pesticide residues after repeated cooking by boiling, frizzling, or frying.

A systematic method is described for the simultaneous determination of Fusarium mycotoxins (nivalenol, deoxynivalenol, fusarenon-x, diacetoxyscirpenol, neosolaniol, T-2 toxin, HT-2 toxin, butenolide, moniliformin, and zearalenone) in cereals, grains, and foodstuffs. Mycotoxins were extracted with aqueous methanol and purified by a 2-step chromatographic procedure using Amberlite XAD-4 and Florisil columns. The column eluates were concentrated and spotted on a thin layer chromatographic (TLC) plate which was then developed in CHCL3-methanol (93 + 7) and toluene-acetonemethanol (5 + 3 + 2). Each mycotoxin was quantitated by gas chromatography (GO and TLC densitometry. The minimum detectable concentrations (μg/kg) in various test materials were: nivalenol, deoxynivalenol, and fusarenon-x, 2.0; diacetoxyscirpenol, neosolaniol, T-2 toxin, and HT-2 toxin, 80; zearalenone, 10; butenolide, 30; and moniliformin, 50. Recoveries of the mycotoxins added to various cereal samples at 1.0-2.0 Mg/g were greater than 71% and averaged 85%.

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LC/MS/MS was developed to determine the residues of bithionol (BTN), bromofen (BMF), nitroxynil (NTX), oxyclozanide (OCZ), and tribromsalan (TBS) in milk. Samples were extracted with ethyl acetate and cleaned up by liquidliquid separation with acetonitrile and n-hexane. The compounds were determined by RP-LC using a C18 column with 0.1 formic acidmethanol. Mass spectral acquisition was performed in the negative mode by applying selected-reaction monitoring. The method was validated in milk spiked with these compounds at 5600 g/kg; average recoveries were in the range 83.897.1, with RSD values of 1.48.0. The interassay RSDs were less than 11. The LODs of these compounds in milk were 0.1 g/kg. The method was applied to 24 raw milk samples. The concentration of these compounds in all samples was lower than the Japanese maximum residue limits. The method is rapid, sensitive, and specific for monitoring residues of BTN, BMF, NTX, OCZ, and TBS in milk.

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