Determination of ethylenethiourea and propylenethiourea in tomato products and in fruit purees

Simultaneous determination of maneb and its main metabolites in tomatoes by liquid chromatography using diode array ultraviolet absorbance detection

“…However, all these methods require derivatization steps, and most of them are insufficiently specific to distinguish between residues of individual EBDCs. LC techniques coupled with UV [16][17][18][19], MS [20] or electrochemical detection [21,22] have been reported for ETU determination. Aprea et al [23] have individually determined maneb and ETU using gas and liquid chromatography, respectively.…”

Determination of ethylenethiourea (ETU) and propylenethiourea (PTU) in foods by high performance liquid chromatography–atmospheric pressure chemical ionisation–medium-resolution mass spectrometry

“…Subsequent steps in this method are cleanup with further diatomaceous earth and alumina. Improved recovery from diatomaceous earth has been achieved by pH adjustment (Krause 1989a;Bolzoni et al 1993) and salting-out with KF combined with pH buffering (Nitz et al 1982;Maruyama 1994;Ahmad et al 1995). Oxidation of ETU during extraction has been noted to be a cause of poor recovery and either sodium ascorbate (Otto et al 1977) or cysteine hydrochloride (Sack 1995) have been employed as antioxidants during extraction.…”

“…Several workers have reported methods based on UV detection (Lehotay et al 1992;Ahmad et al 1995;Kontou et al 2001;Garcinuno et al 2004) but detection limits have usually been greater than 0.01 mg/kg. Electrochemical detection has also been employed and affords good sensitivity (Krause 1989a;Bolzoni et al 1993;Matuyama et al 1994) but these methods still involve tedious clean-up steps.…”

“…Although GC of underivatized ETU is possible, most workers attempting GC have found that reliable determination is possible only after derivatization, S-butylation having been widely employed, as, for example, in the AOAC method (AOAC 1995). The use of derivatization, however, requires additional preparation steps which increase the time taken for analysis, and may also increase the possibility of errors and of low recoveries (Bolzoni et al 1993). HPLC has the advantage that derivatization may be unnecessary.…”

Optimization of a matrix solid-phase dispersion method with subsequent clean-up for the determination of ethylene bisdithiocarbamate residues in almond samples

“…As a consequence, there is a clear tendency toward the application of liquid chromatography coupled with UV (LC-UV) [17][18][19][20], mass spectrometry (LC-MS) [21,22] or electrochemical detectors [23,24]. Previous experiments have demonstrated the suitability of coupling LC-UV for the simultaneous determination of ETU and EBIS in tomatoes.…”