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This study reports the equilibrium solubility for monobenzone in methanol, ethanol, n-propanol, isopropanol, n-butanol, acetonitrile, ethyl acetate, acetone, 1,4-dioxane, cyclohexane, N,N-dimethylformamide (DMF), N-methyl-2-pyrrolidinone (NMP), n-hexane, n-octanol, and water that was determined by means of the isothermal method between 283.15 and 313.15 K under p = 101.1 kPa. The maximum value of monobenzone solubility was 0.6316 in mole fraction at 313.15 K dissolved in ethyl acetate, but the least data was achieved in water. The solubility of monobenzone increased with the rising temperature and the order followed in the 15 pure solvents was ethyl acetate (0.6316, 313.15 K) > 1,4-dioxane (0.4350, 313.15 K) > methanol (0.1356, 313.15 K) > acetonitrile (0.1247, 313.15 K) > (ethanol, isopropanol) > n-propanol (0.09942, 313.15 K) > n-butanol (0.08346, 313.15 K) > n-octanol (0.03546, 313.15 K) > cyclohexane (8.020×10–3, 313.15 K) > n-hexane (3.133 × 10–3, 313.15 K) > NMP (2.372 × 10–4, 313.15 K) > DMF (1.145 × 10–4, 313.15 K) > acetone (4.032 × 10–5, 313.15 K) > water (3.019 × 10–5, 313.15 K). There was no existence of processes such as solvation or polymorphic transformation during the entire experiment. Several models covering the modified Apelblat, λh, Wilson, and non-random two-liquid models were applied to correlate and calculate monobenzone solubility data in fifteen monosolvents. Results showed that the modified Apelblat equation provided the best results with the experimental ones. The largest relative average deviation and root-mean-square deviation were no more than 4.74 × 10–2 and 1.81 × 10–3, respectively.

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BACKGROUND: Sulfamethazine (SMZ), a veterinary drug widely used in animal husbandry, is harmful to human health when excess residues are present in food. In this study, a fast, reliable, and sensitive immunochromatographic assay (ICA) was developed on the basis of the competitive format by using time-resolved fluorescent nanobeads (TRFN) as label for the detection of SMZ in egg, honey, and pork samples. RESULTS: Under optimized working conditions, this method had limits of detection of 0.016, 0.049, and 0.029 ng mL −1 and corresponding linear ranges of 0.05 to 1.00, 0.05 to 5.00, and 0.05 to 1.00 ng mL −1 in egg, honey, and pork samples, respectively. The recovery experiments showed that the average recoveries ranged from 90.5% to 113.9%, 82.4% to 112.0%, and 79.8% to 93.4% with corresponding coefficients of variation of 4.1% to 11.7%, 7.5% to 11.5%, and 4.8% to 8.7% for egg, honey, and pork samples, respectively. The developed TRFN-ICA was also systematically compared with high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) by analyzing 45 actual samples from egg, honey, and pork. CONCLUSION: Overall, the developed TRFN-ICA had high reliability and excellent potential for the ultrasensitive detection of SMZ for food safety monitoring, also providing a universal platform for the on-site detection of other targets.