ABSTRACT
RATIONALE: Parabens, the alkyl esters of 4-hydroxybenzoic acid, are a family of compounds widely used as preservatives in cosmetic products, including for children, and some are permitted in foods. Parabens are known to be weak endocrine disruptors because they interfere with the function of endogenous hormones through binding to estrogen receptors. Therefore, the levels of parabens in biological samples indicate endocrine-disruptive exposure. In particular, hair samples can provide information on accumulated exposure to parabens. METHODS: For monitoring of long-term exposure to parabens, an improved analytical method for rapid and direct determination in hair sample was developed involving ultra-performance liquid chromatography-tandem mass spectrometry using on-line extraction. Five parabens (methyl-, ethyl-, propyl-, butyl- and benzylparaben) were separated within 10 min after incubation with 1 N HCl. Parabens were separated using a Waters BEH C18 column (2.1 mm × 100 mm, 1.7 µm) and a mobile phase consisting of 10 mM ammonium acetate in water and acetonitrile with a gradient program at a flow rate of 300 µL/min. The analysis of the separated parabens was monitored with electrospray negative ionization tandem mass spectrometry. RESULTS: The linearity of the method was demonstrated by r2 ≥ 0.994. The limits of detection as defined by a signal-to-noise ratio of 3 were 1-5 ng/g. The mean concentration of the five parabens in hair of human subjects was measured to be 55.6 ± 24.3 to 136.9 ± 48.5 ng/g. CONCLUSIONS: The levels of parabens in hair samples may play an important role in understanding probable endocrine-disruptive exposure, and the described method could be used to evaluate and monitor long-term exposure to parabens as endocrine disruptors.
Subject(s)
Chromatography, Liquid/methods , Environmental Exposure/analysis , Hair/chemistry , Parabens/analysis , Tandem Mass Spectrometry/methods , Adult , Endocrine Disruptors/analysis , Female , Humans , Limit of Detection , Reproducibility of Results , Signal-To-Noise Ratio , Spectrometry, Mass, Electrospray IonizationABSTRACT
RATIONALE: Volatile organic compounds (VOCs) are ubiquitous environmental pollutants that have a high vapor pressure at room temperature. Some VOCs have been classified as carcinogenic to humans by the International Agency for Research on Cancer (IARC), because they can bind to DNA and cause cell mutations. Therefore, monitoring of VOCs in human urine is very important to evaluate the correlation between exposure to VOCs and human disease. METHODS: We have developed an improved analytical method for the simultaneous determination of VOCs with a wide range of polarities in human urine samples by headspace solid-phase microextraction (HS-SPME) coupled to gas chromatography/mass spectrometry (GC/MS). In the improved method, a bi-polar carboxen-polydimethylsiloxane (CAR/PDMS) fiber was used for the optimized extraction of 15 VOCs with a wide range of polarities, including benzene, toluene, ethylbenzene, xylenes (BTEX), alkylbenzenes, cresols, and naphthalene, in human urine samples. Extracted VOCs from the human urine were effectively separated by GC using a mid-polarity column (DB-35, 35% phenylmethylpolysiloxane) and monitored by MS using extracted ion monitoring (EIM) mode. RESULTS: Under the optimized method, the linearity of the calibration curves was greater than 0.993. The limits of detection (LODs) at a signal-to-noise (S/N) ratio of 3 were 0.3-0.6 ng/mL. The coefficients of variation were in the range of 0.1-9.7% for within-day variation and 0.2-14.2% for day-to-day variation. CONCLUSIONS: The method was shown to be rapid and simple for the simultaneous determination of VOCs with a wide range of polarities in human urine and it could be applied to monitoring and to biomedical investigations to check exposure to VOCs. Copyright © 2017 John Wiley & Sons, Ltd.
Subject(s)
Gas Chromatography-Mass Spectrometry/methods , Solid Phase Microextraction/methods , Volatile Organic Compounds/urine , Humans , Limit of Detection , Linear Models , Reproducibility of Results , Volatile Organic Compounds/chemistry , Volatile Organic Compounds/isolation & purificationABSTRACT
The incidence and impact of malnutrition on acute coronary syndrome (ACS) remain unclear. This study aimed to evaluate the prevalence, clinical relevance, and prognostic outcomes of malnutrition in patients with ACS treated with percutaneous coronary intervention. This retrospective study included 1930 consecutive patients with ACS undergoing percutaneous coronary intervention and assessed their nutritional status using 3 scoring systems: Controlling Nutritional Status score, nutritional risk index (NRI), and prognostic nutritional index (PNI). The primary endpoint was all-cause mortality. The Controlling Nutritional Status, NRI, and PNI scores showed that 5.2%, 17.5%, and 3.9% of patients were moderately or severely malnourished, respectively. During a median follow-up of 67.2 months (interquartile range: 46.8-88.5 months), 74 (3.8%) patients died. Malnutrition was associated with a significantly increased risk for all-cause mortality compared with good nutrition (adjusted hazard ratios for moderate and severe malnutrition, respectively: 5.65 [95% confidence interval: 3.27-9.78] and 15.26 [7.50-31.05] for the NRI score, 5.53 [2.10-14.49] and 11.08 [5.69-21.59] for the PNI; P < .001). The current findings demonstrated that malnutrition is prevalent among patients with ACS and is closely associated with increased mortality. Further study is needed to evaluate the effects of nutritional interventions on the outcomes of patients with ACS.