[Analysis of spinosad in animal and fishery products by LC-MS].

We investigated the determination of spinosyn A and spinosyn D, the active ingredients of spinosad, in animal and fishery products by liquid chromatography with mass spectrometry (LC-MS). The sample was homogenized with 1 mol/L dipotassium hydrogenphosphate aqueous solution and extracted with acetone-n-hexane under mildly alkaline conditions. After n-hexane-acetonitrile partitioning using an EXtrelut(®) column, the extract was cleaned up on a tandem SAX/PSA mini-column, and examined by means of fragmenter-voltage-switching ESI-SIM mode LC-MS. Mean recoveries (n=5) of spinosyn A and spinosyn D from eleven kinds of fortified samples at the analyte concentration of 0.01 µg/g and 0.05 µg/g ranged from 76.1% to 93.8% (RSD≤8.7%) and from 75.1% to 104.1% (RSD≤8.6%), respectively.

Study on detection of drugs in slimming health foods using GC-MS/MS.

The determination of five drugs, fenfluramine (FEN), N-nitrosofenfluramine (NFE), sibutramine (SIB), mazindol (MAZ) and phenolphthalein (PHP), was studied in slimming health foods using GC-MS/MS. These drugs have been detected at high rates, especially in slimming health foods. Prolonged or excessive consumption of non-approved or unauthorized pharmaceuticals may cause serious adverse health consequences. In this study, samples were extracted with methanol and ultrasonication. Analyses were performed by GC-MS/MS, using established MS/MS parameters in the electron ionization (EI) mode and chemical ionization (CI) mode. In the EI mode, the recoveries of five drugs from several types of slimming health foods such as tablets, capsules and tea-bags spiked at 1 µg/mg (except PHP, spiked at 4 µg/mg) were in the range of 85.0-110.7% and 100 µg/mg (except PHP, spiked at 200 µg/mg) were 94.9-102.9%, respectively. In the CI mode, good recoveries of 80.3-102.2% (spiked at low concentration) and 92.8-103.2% (spiked at high concentration) were also obtained. We evaluated the present method using four slimming health foods, in which drugs had previously been detected. The results were similar to the previous results. These findings indicate that the present procedure for evaluating five drugs in slimming health foods by means of GC-MS/MS is useful.

[Multiresidue analysis of PCB, organochlorine pesticides and chlordanes in marine products by GC-micro ECD].

A multiresidue method using dual-injection, dual-column, and dual-micro electron capture detection gas chromatography (dual-column GC-µECD) was developed for the determination of PCB, organochlorine pesticides and chlordanes in marine products. The sample was extracted with hexane-acetone (2 : 1), and the extract was cleaned up by gel permeation chromatography(GPC)/solid-phase extraction (SPE). The GPC fraction was selectively collected, and loaded directly onto a graphitized carbon/PSA 2-layered column. After fractionation by 4% hydrated silica-gel column chromatography, each fraction was determined by dual-column GC-µECD. Recoveries of PCB, organochlorine pesticides and chlordanes were in the ranges of 84-109% (RSD ≤ 21.6%), 74-117% (RSD ≤ 14.6%) and 69-114% (RSD ≤ 12.9%), respectively. This method is superior to single chromatography for the determination of total PCB, and should be useful for monitoring of these pollutants in marine products.

[Analysis of acephate, methamidophos and omethoate in animal and fishery products, and honey by LC-MS].

We studied the simultaneous determination of acephate, methamidophos, and omethoate in animal and fishery products, their processed foods, and honey by means of liquid chromatography coupled with mass spectrometry (LC-MS). The sample was extracted with ethyl acetate in the presence of anhydrous Na(2)SO(4) (and diatomaceous earth for honey). An aliquot of the crude sample extract was loaded into the GPC system, and the pesticide fraction was selectively collected. The extract was cleaned up on a PSA mini-column, and determined by a column-switching ESI-SIM mode LC-MS. Mean recoveries (2 replicates x 5 days) of compounds from eleven kinds of samples, except honey, fortified at the analyte concentration of 0.05 microg/g were from 71.4% to 98.4%. The repeatability relative standard deviation values were < or =12.5%, and the intermediate reproducibility relative standard deviation values were < or =14.1%. In honey, the recoveries were improved to 97.6-98.6% by using highly purified surrogates.

Simultaneous identification/determination system for phentolamine and sildenafil as adulterants in soft drinks advertising roborant nutrition.

An easily available, simultaneous identification/determination procedure for phentolamine (PHE) and sildenafil (SIL) in adulterated dietary supplements was established by using a combination of three different analytical methods; thin-layer chromatography (TLC), liquid chromatography-mass spectrometry (LC/MS) and a high-performance liquid chromatography (HPLC)/photo-diode-array. The sample solution for TLC was applied to silica gel 60 F(254) plates with chloroform/ammonia solution (28)/methanol (70:5:3, lower layer) and chloroform/diethylamine/methanol (15:3:2) as the developing solvent. Spots were located under UV radiation at 254 nm. Mass spectra of PHE and SIL by LC/MS were investigated with electrospray ionization (ESI) interface, under both positive and negative ion mode. The HPLC analysis was performed on a column of Wakosil 5C18 (4.6 mm x 150 mm, 5 microm) with water/methanol/acetonitrile/triethylamine (580:250:170:1) adjusted with phosphoric acid to pH 3.0 as the mobile phase, and the effluent was monitored with a photo-diode-array detector. Quantitative HPLC analysis of PHE and SIL were detected at 280 nm. When this procedure was applied to commercial soft drinks, PHE and SIL were identified and determined at a concentration of 17 mg PHE and 44 mg SIL per bottle, respectively. The procedure described here is available for the screening of PHE and SIL in adulterated supplements.

[Simultaneous analysis of four diuretic drugs by HPLC and its application to health food supplements advertising weight reduction].

A high-performance liquid chromatographic (HPLC) method for the simultaneous analysis of triamterene, trichlormethiazide, furosemide and spironolactone is presented for application in the examination of health food supplements advertising weight reduction and in the analysis of pharmaceuticals. The HPLC assay was performed under gradient conditions using a Wakosil ODS 5C18 column (5 microns, 150 x 4.6 mm i.d.). The mobile phase consisted of a gradient program with a mixture of water and acetonitrile containing 0.1% triethylamine adjusted with phosphoric acid to pH 3.0: from 0 to 6 min, 15% acetonitrile; from 6 to 20 min, linear gradient from 15 to 50% acetonitrile; and from 20 to 40 min, 50% acetonitrile. The column effluent was monitored from 0 to 20 min at 260 nm and from 20 to 40 min at 235 nm. The calibration curves of the four drugs showed good linearity and the correlation coefficients were better than 0.999 in all cases. The lower limits of detection were approximately 40 ng for each drug. Commercially available health food supplements and pharmaceuticals were analyzed after extraction with a mixture of methanol and acetic acid (99:1). The procedure described here is suitable for the screening of four diuretic drugs in adulterated supplements and for the quality control of pharmaceuticals with minimal sample preparation.