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To determine fluoride in toothpaste samples by ion chromatography,the solution of NaHCO3 and the solution of Na2B4O7-NaOH were selected as eluents respectively to optimize chromatographic detection conditions. Either the 0. 45～1.0 mmol/L NaHCO3 solution or the 5.0～20. 0 mmol/L NaB4O7-1. 0～2.0 mmol/L NaOH solution as eluents could effectively separate the chromatographic peak of fluoride in toothpaste samples from acetate and formate and accurately quantify the contents of fluoride in toothpaste samples. The recovery rates,precision(relative standard deviation) and detection limit were 92.5％～100. 2％ ,＜0. 6％ and 0. 208 mg/kg respectively. The data obtained by ion chromatography using NaHCO3 solution as eluent more approached to that by selective-fluoride-ion-electrode.
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ve To explore the hygienic safty of cosmetics for special use. Methods The detection and analysis on the hygienic safety of 432 domestic cosmetics for special use saled in Guangdong provincial markets were carried out in 2000. Results The orders of qualified rates of cosmetics for special use from high to low were as fol-lows: deodorant cosmetics (100%), hair-removing cosmetics(88.89% ), breast massage (80.00% ), antisunburn lotion (77.88%), fading cream(75.68% ). hair nourishment(64.29% ), beautifying cosmetics(50.00% ), hair dye (40.74%) and hair pem(28.57%). The highest unqualified rate of hygienic safety test on cosmetics was 17.28% for Ames test, next was 14.81% for chromosome aberration test on mammalian cells in vitro, 14.13% for eye irritation test and 10.88% for skin allergic reaction. Conclusion The management on the hygienic safety of cosmetics for special use should be strengthened further.
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ve To increase the analytical efficacy and the sensitivity of determination of trace chloroform and tetrachloro-methane in water. Methods Headspace solid phase microextraction (HSSPME) analysis was applied to replace the traditional headspace method in determination of trace chloroform and tetrachloro-methane in water. Results The lowest detection limits were 0.05?g/L for chloroform and 0.005?g/L for tetrachloro-methane respec-tively. The precisions and accuracies all accorded with the requirements of determination. Conclusion The method of HSSPME was easy and rapid to operate, revealed reliable and accurate results and good practicability. It also showed higher sensitivity without any organic solvent, compared with that of traditional headspace method.
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0.999).The relative standard derivations (RSDs) were 0.2%-5.0%, the rates of recovery were 91.1%-108.5%. The detection limits for analysis ranged from 1.3 mg/kg to10 mg/kg. Conclusion The method presented in the paper is sensitive, accurate and suitable for the determination of organic acids cosmetic samples.
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Objective To establish an IC method for determination of iodate, bromate, nitrite in cosmetics, food and salt by suppressed anion-exchange chromatography and ion-exchange with the addition of post column reagent. Methods A high capacity anion exchange column, Ion Pac9-HC column was used by 9 mmol/L sodium carbonate as eluent, and the flow rate was set up at 1.3 ml/min,an auto-suppression external water mode was used, 0.5 g/L o-dianisidine. 2HCl(ODA)+5 g/L KBr+20%methanel+5.6% nitric acid was used as post column reagent , the flow was set up 0.7 ml/min. The post column reaction (PCR) temperature was 60 ℃ and the visible absorbance detection at 450 nm. Samples were pretreated and analysed. Results The influence of pH of samples and coexist anion on determination was discussed. The detection limit(MDL) of the present method was 0.008-0.10 mg/kg, the recovery rates of the method were 92.0%-109.0% and the relative standard deviation (RSD) were 0.1%-7.2%. Conclusion This method is accurate, sensitive and suitable for trace analysis (?g/kg) of cosmetics and foods samples.
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Objective To study the method for determination of nipacide PX and triclosan in disinfectant by high performance liquid chromatography. Methods High performance liquid chromatography, based on the mobile phase (CH3CN:H2O=60:40, pH=3.0) and diode array detector(DAD, ?= 280 nm), was chosed to determine nipacide PX and triclosan in disinfectant. Results The detection limit of nipacide PX was 2.48 ng and triclosan was 2.08 ng. The rate of recovery was 95.4%-103.3%,the relative standard deviations(RSD) was 0.6%-3.4%. Conclusion The method is simple, precise and suitable for the determination of nipacide PX and triclosan in disinfectant.