Amygdalin in bitter and sweet seeds of apricots

Hydrogen cyanide (HCN) poisoning due to amygdalin (AMY) in apricot seeds is one of the public health issues in Turkey. The aim of this study was to investigate the AMY content of 13 different apricot seeds including bitter and sweet ones, and which are either sulfurized or roasted. The AMY content was determined by a high-performance liquid chromatography. Release of HCN was predicted and total amount of seeds which can cause poisoning was calculated. The mean AMY content of bitter seeds was 26 ± 14 mg g^?1 and that of sweet seeds was 0.16 ± 0.09 mg g^?1. The consumption of small amounts of bitter seeds may cause cyanide poisoning.     

Investigation of naphthalene contamination in olive oil from Greece

Abstract

Incidents of using naphthalene in olive orchards as a repellent of olive fly (Bactrocera oleae) have recently been recorded. Naphthalene, the primary ingredient of mothballs, is described to be diluted in plastic bottles and hanged on the trees releasing its characteristic odor which is supposed to repel olive fly. Since naphthalene has been characterized as possibly carcinogenic to humans and animals, it was considered essential to monitor olive oils regarding their potential contamination with this specific pollutant. To this goal, a simple, sensitive and reliable analytical method for the determination of naphthalene in olive oil has been developed. The method involves extraction with ethyl acetate: acetonitrile (1:1) and determination of naphthalene using gas chromatography triple quadrupole mass spectrometry. The method was validated in four fortification levels, 0.005, 0.01, 0.05, and 0.1?mg/kg in accordance with the EU requirements. The obtained results were acceptable as far as validation criteria are concerned, given recoveries between 71% and 87% and RSDs between 5% and 24%. The limit of determination for naphthalene was set at 0.005?mg/kg based on the lowest concentration level being validated with acceptable accuracy. The analytical technique was successfully applied to 75 olive oil samples collected from oil mills in Greece and no positive results of naphthalene were detected.     

Rapid liquid chromatographic analysis of Metoclopramide in pharmaceutical preparations

A sensitive, accurate and reproducible method for the analysis of metoclopramide, a gastrointestinal drug, has been described. An isocratic HPLC elution method was employed which requires about 10 minutes to be performed. The concentration of metoclopramide hydrochloride preparations was found to be 95.1 ±0.3% and 94.21 ±0.25% in tablet and injection formulations, respectively.     

Analyses of phenolic compounds occurring in olive oil mill wastewaters by GC–MS

Phenolic compounds in olive oil mill wastewaters were analysed by HRGC–MS after extracting the acidified solution with ethyl acetate and derivatization with N,O-bis(trimethylsilyl)trifluoroacetamide. Both simple and complex phenols were detected with the latter being the most abundant. 1,2-dihydroxybenzene (catechol), p-hydroxyphenyl ethanol (tyrosol), 3,4-dihydroxyphenyl ethanol (hydroxytyrosol) and 4-hydroxy-3-methoxyphenyl ethanol (homovanillyl alcohol) predominated among the simple phenols using a gas chromatograph coupled with a mass selective detector.     

Determination of 4-nonylphenol in carp blood samples by solid phase extraction and chromatographic techniques

In this study, selective methods were developed for isolation, purification, separation and determination of 4-nonylphenol (4NP) in biological samples. Several methods such as high-performance liquid chromatography (HPLC) with fluorescence and diode array detection and gas chromatography coupled to mass spectromotry (GC-MS) are described for the simultaneous determination of 4NP. The nonylphenols in the plasma of fish were extracted through solid phase process by using octadecyl, polymeric and octadecyl endcapping sorbents. The average recoveries in plasma samples spiked with 4NP of levels 1?µg?mL^?1 were between 80–95% using added surrogate standards. The aim of this study was to determine whether trace amounts of 4NP in fish plasma samples could be detected by solid phase extraction and chromatographic methods (HPLC, GC-MS). This technique of monitoring the levels of endocrine-disruptors in plasma samples is consistent, reliable as well as inexpensive.     

Standard purity and response factors of perfluorinated compounds

It has been reported that the relative response factors of isotopically labeled standards and unlabeled standards of the same perfluorinated compounds could be different. Individual (100 ng mL^?1) solutions of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) were analyzed using high-performance liquid chromatography tandem mass-spectrometry under negative-ion electrospray to detect any impurities present down to 0.5%–0.1% relative to the major component. Purity of the standards ranged from approximately 86% to ≥ 97%. Standard solutions of unlabeled and isotopically labeled materials were analyzed to compare the response factors of isotopically labeled analytes versus their nonlabeled counterparts in three different matrices at equivalent concentrations: organic solvent (methanol), serum extract, and water present individually and concurrently. Not all labeled analytes have the same response factor as their nonlabeled complement, and in at least one case the matrix in which the standard is present may cause significant suppression of response. Standard solutions of electrochemical fluorination produced PFOA and PFOS were quantified under multiple reaction monitoring mode, using calibration curves prepared from standards consisting primarily of linear standards only. The use of linear only standards may cause under-prediction of concentrations, and that the working range of these standards may be limited.     

The estimation of bioconcentration factors of aromatic hydrocarbons by high‐performance liquid chromatography

The determination of Bioconcentration Factors (BCF) via HPLC capacity factors (k') has been studied, including the effect of column type and mobile phase composition on the correlation between log BCF and log k’. Values of BCF correlate well with the phenylsilica column capacity factors. The phenylsilica column followed by C18 column give better correlations than either C8 or C2 column. The use of HPLC with phenylsilica as stationary phase and methanol‐water as mobile phase in the prediction of BCF can be at least as good or better than the use of n‐octanol/water partitioning system. There are no significant differences in the correlations between log k’ and log BCF with the changes of methanol concentration in the mobile phase, and it seems that a high proportion of methanol in the eluent is required to obtain good results.     

Removal of pesticides from water samples by adsorption with fatty acids supported on barium sulphate

Oleic or linoleic acid supported on barium sulphate was used to remove atrazine and terbuthylazine in the range of 0.1–2.0 μg/L using spiked water samples. The sorption of atrazine depends on the stirring time and the best value is 150 min. Terbuthylazine is removed well with a stirring time of 60 min and its adsorption is about 90%. Detection of the residual pesticide in treated waters, after solid phase extraction (SPE), was carried out by GC‐MS operating in selected ion monitoring (SIM) using a calibration curve by direct injection of standard solutions of herbicide.     

Chemical and colloidal analyses of natural seep water collected from the exploratory studies facility inside Yucca Mountain,Nevada, USA

Yucca Mountain is being considered as a geological repository for the USA’s spent nuclear fuel and high-level nuclear waste. Numerous groundwater seeps appeared during March 2005 within the exploratory studies facility (ESF), a tunnel excavated in the mountain. Because of the relevance to radionuclide transport and unsaturated zone-modeling studies, we analyzed the seep samples for major anions and cations, rare earth elements, and colloids. Major ion species and elemental concentrations in seep samples reflect interaction of the water with the volcanic rock and secondary calcites. Elemental fractograms from flow-injection field-flow fractionation ICP–MS scans detected Br, Ca, Cl, Cu, Fe, I, Mg, Si, Sr, W, and U at void fractions, suggesting they may be present in the form of dissolved anions. Colloids approximately 10 nm in hydrodynamic diameter, possibly calcite, were also present in the seepage samples. Geochemical calculations indicate, however, these may be an artifact (not present in the groundwater) which arose because of loss of CO₂ during sample collection and storage.     

Determination of 27 pharmaceuticals and personal care products (PPCPs) in water: The benefit of isotope dilution

• Isotope dilution method was developed for the determination of 27 PPCPs in water. • The established method was successfully applied to different types of water samples. • The correction effect of corresponding 27 ILSs over 70 d was investigated. • Benefit of isotopic dilution method was illustrated for three examples. Pharmaceuticals and personal care products (PPCPs) are a unique group of emerging and non-persistent contaminants. In this study, 27 PPCPs in various water samples were extracted by solid phase extraction (SPE), and determined by isotope dilution method using liquid chromatography coupled to tandem triple quadruple mass spectrometer (LC-MS/MS). A total of 27 isotopically labeled standards (ILSs) were applied to correct the concentration of PPCPs in spiked ultrapure water, drinking water, river, effluent and influent sewage. The corrected recoveries were 73%–122% with the relative standard deviation (RSD)<16%, except for acetaminophen. The matrix effect for all kinds of water samples was<22% and the method quantitation limits (MQLs) were 0.45–8.6 ng/L. The developed method was successfully applied on environmental water samples. The SPE extracts of spiked ultrapure water, drinking water, river and wastewater effluent were stored for 70 days, and the ILSs-corrected recoveries of 27 PPCPs were obtained to evaluate the correction ability of ILSs in the presence of variety interferences. The recoveries of 27 PPCPs over 70 days were within the scope of 72%–140% with the recovery variation<37% in all cases. The isotope dilution method seems to be of benefit when the extract has to be stored for long time before the instrument analysis.