Determination of 14 illicit drugs and major metabolites in human hair by UPLC-MS/MS combined with ion switching technology / 国际药学研究杂志

Objective: To establish an UPLC-MS/MS method for the determination of 14 illicit drugs and major metabolites in human hair. Methods: Samples of hair were pulverized with an SPEX 6875 Freeze Mill, and then extracted with methanol under ultra-sonication. An ACQUITY UPLC HSS C18 column was used with 20 mmol/L ammonium acetate water solution(containing 0.1% formic acid)-methanol as mobile phase at a flow rate of 0.3 ml/min. Multiple reaction monitoring(MRM)mode was performed combined with the ion switching technology for quantification in five sections. The 11-nor-9-carboxy-tetrahydrocannabinol(THCCOOH)was detected by the negative ion scanning mode, while the others were detected by the positive ion scanning mode. Results: The liner calibration curve of morphine, 6-monoacetylmorphine, codeine, heroin, ketamine, 3, 4-methylenedioxymethamphetamine, 3, 4-methylenedioxyamphetamine, amphetamine, methamphetamine, cocaine, benzoylecgonine, pethidine, Δ9- tetrahydrocannabinol, and 11-nor- 9- carboxy-tetrahydrocannabinol showed a good linearity in the concentration range of 0.05-10.00(r=0.9964), 0.05-10.00(r= 0.9912), 0.05-10.00(r=0.9967), 0.05-10.00(r=0.9933), 0.02-10.00(r=0.9961), 0.02-10.00(r=0.9938), 0.05-10.00(r=0.9782), 0.05-10.00(r=0.9900), 0.02-10.00(r=0.9974), 0.02-10.00(r=0.9949), 0.02-10.00(r=0.9959), 0.02-10.00(r=0.9957), 0.10-20.00 (r=0.9887), and 0.10-20.00 ng/mg(r=0.9911), respectively. The lowest detection limit was 0.01, 0.01, 0.01, 0.02, 5.00×10-3, 5.00× 10-3, 0.02, 0.02, 5.00×10-3, 5.00×10-3, 5.00×10-3, 5.00×10-3, 0.05, and 0.05 ng/mg, respectively. The RSD of inter-day and intra-day was less than 20%. The relative recovery was more than 55%, and the RSD was less than 15%. Conclusion: The method is accurate, sensitive and suitable for the detection and quantification of 14 illicit drugs and major metabolites in human hair.

Expression Pattern and Role of Klotho in Human Hair Follicles

BACKGROUND: Klotho protein plays a pivotal role in aging regulation. However, it is unclear whether klotho is expressed in human hair follicles and is correlated with hair growth. OBJECTIVE: The purpose of this study was to determine the expression pattern and role of klotho in human hair follicles. METHODS: We examined the klotho expression patterns in human hair follicles from young and aged donors. Furthermore, we examined the functional roles of klotho on human hair growth using klotho siRNA and klotho recombinant protein. RESULTS: Interestingly, klotho was expressed in human hair follicles at both gene and protein levels. In hair follicles, prominent klotho expression was mainly observed in the outermost regions of the outer root sheath and hair bulb matrix cells. Quantification of klotho protein expression in young and aged donors showed that klotho expression decreased with aging. In human hair follicle organ culture, klotho silencing promoted premature catagen induction and inhibited human hair growth. Otherwise, klotho protein prolonged human hair growth. CONCLUSION: These results indicate that klotho might be an important regulatory factor for human hair growth and hair cycle change.

Effect of Miscanthus sinensis var. purpurascens Flower Extract on Proliferation and Molecular Regulation in Human Dermal Papilla Cells and Stressed C57BL/6 Mice / 中国结合医学杂志

<p><b>OBJECTIVES</b>To investigate the hair growth-promoting effect of Miscanthus sinensis var. purpurascens (MSP) flower extracton on in vitro and in vivo models.</p><p><b>METHODS</b>MSP flower extract was extracted in 99.9% methanol and applied to examine the proliferation of human dermal papilla cells (hDPCs) in vitro at the dose of 3.92-62.50 μg/mL and hair growth of C57BL/6 mice in vivo at the dose of 1000 μg/mL. The expression of transforming growth factor β1 (TGF-β1), hepatocyte growth factor (HGF), β-catenin, substance P was measured by relative quantitative realtime polymerase chain reaction. Histopathological and immunohistochemical analysis were performed.</p><p><b>RESULTS</b>MSP (7.81 μg/mL) down-regulated TGF-β1 and up-regulated HGF and β-catenin in hDPCs (P<0.01). MSP (1000 μg/mL)-treated mice showed the earlier transition of hair follicles from the telogen to the anagen phase. The number of mast cells was lower in the MSP-treated mice than in other groups (P<0.05 vs. NCS group). Substance P and TGF-β1 were expressed in hair follicles and skin of the MSP group lower than that in negative control. Stem cell factor in hair follicles was up-regulated in the MSP-treated mice (P<0.01).</p><p><b>CONCLUSIONS</b>The MSP flower extract may have hair growth-promotion activities.</p>

3-Deoxysappanchalcone Promotes Proliferation of Human Hair Follicle Dermal Papilla Cells and Hair Growth in C57BL/6 Mice by Modulating WNT/β-Catenin and STAT Signaling

3-Deoxysappanchalcone (3-DSC) has been reported to possess anti-allergic, antiviral, anti-inflammatory and antioxidant activities. In the present study, we investigated the effects of 3-DSC on the proliferation of human hair follicle dermal papilla cells (HDPCs) and mouse hair growth in vivo. A real-time cell analyzer system, luciferase assay, Western blot and real-time polymerase chain reaction (PCR) were employed to measure the biochemical changes occurring in HDPCs in response to 3-DSC treatment. The effect of 3-DSC on hair growth in C57BL/6 mice was also examined. 3-DSC promoted the proliferation of HDPCs, similar to Tofacitinib, an inhibitor of janus-activated kinase (JAK). 3-DSC promoted phosphorylation of β-catenin and transcriptional activation of the T-cell factor. In addition, 3-DSC potentiated interleukin-6 (IL-6)-induced phosphorylation and subsequent transactivation of signal transducer and activator of transcription-3 (STAT3), thereby increasing the expression of cyclin-dependent kinase-4 (Cdk4), fibroblast growth factor (FGF) and vascular endothelial growth factor (VEGF). On the contrary, 3-DSC attenuated STAT6 mRNA expression and IL4-induced STAT6 phosphorylation in HDPCs. Finally, we observed that topical application of 3-DSC promoted the anagen phase of hair growth in C57BL/6 mice. 3-DSC stimulates hair growth possibly by inducing proliferation of follicular dermal papilla cells via modulation of WNT/β-catenin and STAT signaling.

PREHISTORICAL Pediculus humanus capitis INFESTATION: QUANTITATIVE DATA AND LOW VACUUM SCANNING MICROSCOPY / Infestação pré-histórica por Pediculus humanus capitis: análise quantitativa e por microscopia de varredura de baixo vácuo

A pre-Columbian Peruvian scalp was examined decades ago by a researcher from the Oswaldo Cruz Foundation. Professor Olympio da Fonseca Filho described nits and adult lice attached to hair shafts and commented about the origin of head lice infestations on mankind. This same scalp was sent to our laboratory and is the subject of the present paper. Analysis showed a massive infestation with nine eggs/cm2 and an impressive number of very well preserved adult lice. The infestation age was roughly estimated as nine months before death based on the distance of nits from the hair root and the medium rate of hair growth. A small traditional textile was associated with the scalp, possibly part of the funerary belongings. Other morphological aspects visualized by low-vacuum scanning electron microscopy are also presented here for adults and nits.

Há décadas um escalpo peruano, datado do período pré-colombiano, foi examinado por um pesquisador da Fundação Oswaldo Cruz. O Professor Olympio da Fonseca Filho descreveu lêndeas e adultos fixos a fios de cabelos e fez comentários sobre a origem da infecção por piolhos na espécie humana. Este mesmo escalpo foi enviado ao nosso laboratório e é objeto deste artigo. Sua análise mostrou maciça infestação, com nove lêndeas/cm2 em impressionante número de adultos muito bem preservados. O tempo de infestação foi estimado em cerca de nove meses antes da morte, baseado na maior distância entre lêndeas e o couro cabeludo, levando em consideração taxa média de crescimento capilar de 1 cm por mês. Um pequeno pedaço de tecido tradicional peruano foi encontrado associado ao escalpo, provavelmente pertencente ao conjunto de peças usado no ritual funerário. Aqui, apresentamos alguns aspectos morfológicos de adultos e lêndeas vizualizados por microscopia eletrônica de varredura de baixo vácuo.

Research progress of application of human hair keratin materials in regenerative medicine / 国际生物医学工程杂志

As many naturally-derived proteins,keratins have intrinsic biological activity,good biocompatibility and are biodegradable.Human hair keratins,as one type of the autogenous proteins,also have low immune rejection.Compared to other autogenous materials,human hair keratins come from a variety of sources and show attraction in field of regenerative medicine.The human hair keratins applied in neural implant materials,wound dressing,cell culture substrates,drug delivery system and soft tissue reconstructions,which are based on hydrogels,scaffolds coating,films and composite materials present huge development potential in regenerative medicine.

Quantitative and Qualitative Estimation of Bacteria Contaminating Human Hairs

Human hairs have been known to be easily contaminated with microorganisms. This study was performed in order to measure what bacterial species and how much microorganisms contaminate human hairs in specific place. Virgin human hairs were left at 6 positions in inside corner and beside window in a laboratory for 7 days. The number of viable bacterial cells, which were determined by most probable number method, contaminating the human hairs was measured at a maximum of 10(6)/g hair and a minimum of 10(3)/g hair in inside corner and maximum of 10(6)/g hair and a minimum of 10(3)/g hair beside window. The bacterial cells-contaminating human hairs were observed via fluorescence light microscopy after 4',6-diamino-2-phenylindole (DAPI) staining. The bacterial community contaminating human hairs was analyzed via the thermal gradient gel electrophoresis (TGGE) technique, based on the diversity of the 16S-rDNA variable region. In total, approximately 20 bacterial species were detected from 12 groups of hair samples. In this study, general experimental methods-fluorescence staining, TGGE and MPN-were combined to develop new method for observation and estimation of bacteria contaminating human hairs.

Quantitative and Qualitative Estimation of Bacteria Contaminating Human Hairs

Human hairs have been known to be easily contaminated with microorganisms. This study was performed in order to measure what bacterial species and how much microorganisms contaminate human hairs in specific place. Virgin human hairs were left at 6 positions in inside corner and beside window in a laboratory for 7 days. The number of viable bacterial cells, which were determined by most probable number method, contaminating the human hairs was measured at a maximum of 10(6)/g hair and a minimum of 10(3)/g hair in inside corner and maximum of 10(6)/g hair and a minimum of 10(3)/g hair beside window. The bacterial cells-contaminating human hairs were observed via fluorescence light microscopy after 4',6-diamino-2-phenylindole (DAPI) staining. The bacterial community contaminating human hairs was analyzed via the thermal gradient gel electrophoresis (TGGE) technique, based on the diversity of the 16S-rDNA variable region. In total, approximately 20 bacterial species were detected from 12 groups of hair samples. In this study, general experimental methods-fluorescence staining, TGGE and MPN-were combined to develop new method for observation and estimation of bacteria contaminating human hairs.

High levels of Mercury and Lead detected by hair analysis in two Venezuelan environments / Altos níveis de Mercúrio e Chumbo detectados pela análise de cabelo em dois ambientes venezuelanos

Mercury and Lead concentrations obtained by ICP-OAS analysis of human hair from riverside communities along the Orinoco river in the Amazon state (Venezuela) were compared with those from Caracas, Venezuela. Taking into account the characteristics of these two environments and the values of the average concentrations of Mercury and Lead, baselines were established suggesting that gold mining activity near the Orinoco river is responsible for the high levels of Mercury in hair from the Amazon state, whereas automobile activity is responsible for high levels of Lead in hair in Caracas.

Concentrações de mercúrio e chumbo obtidas pela análise ICP-OAS de amostras de cabelo humano de comunidades ribeirinhas ao longo do rio Orinoco no estado de Amazonas (Venezuela) foram comparadas com outras de Caracas, Venezuela. Levando em consideração as características desses dois ambientes e os valores das concentrações médias de mercúrio e chumbo, foram estabelecidas linhas basais que sugerem que as atividades de minério de ouro próximo ao rio Orinoco são responsáveis pelos altos conteúdos de mercúrio em cabelo no estado de Amazonas. Entretanto, a indústria automotriz é responsável pelo alto conteúdo de chumbo em cabelo em Caracas.

Construction of lentivirus vector containing human ?-catenin-EGFP and its expression in human hair follicle stem cells / 上海第二医科大学学报

Objective To construct the lentivirus carrying human ?-catenin-EGFP(enhanced green fluorescent protein)and observe its expression in human follicle stem cells.Methods The ?-catenin gene sequence was amplified by RT-PCR from extraction of total RNA of human vascular endothelial cells.TA cloning technique was utilized to acquire gene subcloned pUCm-T-?-catenin.After transformation reaction,candidate clone was further analyzed by PCR and gene sequencing.Then the plasmid was transfected into FT293 cells.After identification by Western blotting,the plasmid was transfected into FT293 cells again for packaging.Infection titer was monitored by green EGFP expression.The expression of ?-catenin-lentivirus in human follicle stem cells were observed under inverted fluorescence microscope.Results The ?-catenin gene was cloned into the lentivirus successfully.The high expression of green fluorescence protein in FT293 cell line was found under fluorescent microscope.Viral titer checked by real-time PCR was about 2.0?108 TU/mL.When the multiplicity of infection(MOI)was 10,the infection efficiency of ?-catenin-lentivirus in human follicle stem cells was nearly 80% after infection 48 h around.After 3 weeks of continuous observation,we found the infection efficiency still keeping in the range of 80%-90%.Conclusion The lentivirus expression vector for ?-catenin was successfully constructed.It can steadily infect human follicle stem cells and the infection efficiency is considerable high.

Determination of dioxins in human hair: Estimation of external and internal exposure to dioxins

<p><b>OBJECTIVES</b>To clarify the origin of dioxin and related compounds (dioxins) in human hair, we determined the amounts of adsorbed dioxins in human hair, and the distribution of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in rats.</p><p><b>METHODS</b>Human hair specimens, packed in a glass column, were exposed to ambient air that was introduced into the column with an air pump for 24 h. Rats were administered TCDD by gavage at doses of 0.2, 0.8, and 1.6 μg/kg body weight. Four weeks after TCDD administration, hair from the back, serum, and adipose tissue were removed under diethyl ether anesthesia. The amounts of dioxins in these samples were analyzed by high resolution gas chromatography with mass spectroscopy.</p><p><b>RESULTS</b>Exposure of the hair specimens to ambient air for one day increased the total toxic equivalent (TEQ) value by 51%. In TCDD-treated rats, the amount of TCDD in hair increased in a dose-dependent manner, and showed a significant positive correlation with that in adipose tissue.</p><p><b>CONCLUSIONS</b>Human hair was found to retain dioxins by both internal and external exposure, and the contribution of external exposure was estimated to be about 40% of the TEQ.</p>

Determination of Dioxins in Human Hair: Estimation of External and Internal Exposure to Dioxins

Objectives: To clarify the origin of dioxin and related compounds (dioxins) in human hair, we determined the amounts of adsorbed dioxins in human hair, and the distribution of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in rats. Methods: Human hair specimens, packed in a glass column, were exposed to ambient air that was introduced into the column with an air pump for 24 h. Rats were administered TCDD by gavage at doses of 0.2, 0.8, and 1.6 μg/kg body weight. Four weeks after TCDD administration, hair from the back, serum, and adipose tissue were removed under diethyl ether anesthesia. The amounts of dioxins in these samples were analyzed by high resolution gas chromatography with mass spectroscopy. Results: Exposure of the hair specimens to ambient air for one day increased the total toxic equivalent (TEQ) value by 51%. In TCDD-treated rats, the amount of TCDD in hair increased in a dose-dependent manner, and showed a significant positive correlation with that in adipose tissue. Conclusions: Human hair was found to retain dioxins by both internal and external exposure, and the contribution of external exposure was estimated to be about 40% of the TEQ.

Effects of Substance P on the Expression of Various Factors to control Hair Growth in Human Hair Follicle Culture / 대한피부과학회지

BACKGROUND: Among constituents of the skin, hair follicle is an organ where nerve fibers with the most highest density are distributed. Recently, it has been reported that neuropeptides, which are secreted by nerve fibers, have important roles in the hair growth and hair cycle change, and that, the expression of various growth factors and apoptosis-related molecules are important in the hair growth and hair cycle change. Therefore, it was thought of import to analyse the relationship between the effect of neuropeptides and the expression of various factors to control hair growth in the hair follicle and hair follicle cells. OBJECTIVE: The purpose of this study was to investigate the relationship between the effect of neuropeptides and the expression of various hair growth-related factors at the level of hair follicle after pretreatment of cultured hair follicles and dermal papilla cells with SP. METHODS: Normal human scalp samples were obtained, and anagen hair follicles and dermal papilla cells were isolated and were cultured in Dulbeco's Modified Eagle's Medium (DMEM) with several combination of supplements in an atmosphere of 5% CO2/95% air incubator. We divided the culture plates into two groups; i.e. control group (DMEM only) and SP group (10-6M SP dissolved in DMEM). The results were evaluated by measuring linear hair growth and hair follicle morphology under a light microscope. Also, after pretreatment of cultured hair follicle and dermal papilla cells with SP, we examined changes of expression of hair growth factors (FGF-7, IGF-1, VEGF), hair growth-inhibitory factors (IL-1alpha, IL-1beta), and apoptosis-related molecules (p53, caspase-3). RESULTS: The following results were obtained. 1. SP did not have any statistically significant effect on the rate of linear hair growth in cultured hair follicles. However, it prolonged the anagen stage of hair cycle. 2. In hair follicles, the expression of FGF-7, a hair growth factor, was increased more than control, while the expression of caspase-3, an apoptosis-related molecule, was decreased more than control. Also, morphological changes as well as the changes of expression of hair growth factors and apoptosis-related molecules were not found in dermal papilla cells. However, the expression of IL-1beta, a hair growth-inhibitory factor, was decreased more than control. CONCLUSION: We can conclude from the results that SP has growth-stimulatory effect and especially prolongs the duration of anagen phase without affecting the rate of linear hair growth. Also, in hair follicles and dermal papilla cells, SP shows hair growth-stimulatory effect at the molecular levels.

Experimental study on the effects of spironolactone on human hair follicles in vitro / 医学研究生学报

0.05). Conclusion: Spironolactone could not enhance or inhibit the growth of hair follicle.

Effects of TNF-alpha and Minoxidil on Human Hair Growth in Vitro / 대한피부과학회지

BACKGROUND: The factors that regulate hair follicle growth are still poorly understood. In vitro models may be useful in elucidating some aspects of hair follicle biology. TNF-alpha is potent inhibitor of hair follicle growth. TNF-alpha induces the formation of a club-like hair follicle, similar to catagen morphology of the hair bulb. Minoxidil induces generalized hypertrichosis when administered systemically, or localized hair regrowth when applied topically to sites of alopecia. OBJECTIVE: The purpose of this study is to investigate the effect of TNF-alpha and minoxidil on human hair growth using in vitro model. METHODS: Healthy human hair follicles without any visible damage were collected, they were cultured in Williams E medium with several combinations of supplements and TNF-alpha and/or minoxidil were added to the media. The results were evaluated by measuring linear hair fiber growth and hair follicle morphology on light microsocopy and by measuring radioisotope uptake of (methyl-3H)thymidine of hair follicle. RESULTS: The following results were obtained from this study. TNF-alpha have inhibitory effect on the rate of linear hair growth in cultured hair follicles. Minoxidil has no stimulatory effect on the rate of linear hair growth and no protective effect on the TNF-alpha induced growth inhibition in cultured hair follicles. CONCLUSION: TNF-alpha has growth-inhibitory effect and minoxidil has no protective effect on the TNF-alpha induced hair change.

Effects of Substance P on the Hair Growth in Human Hair Follicle Organ Culture / 대한피부과학회지

BACKGROUND: In vitro, some neuropeptides, including substance P(SP), act as a growth factor. The cyclic growth of the richly innervated hair follicle offers a model for probing such functions in a complex, developmentally regulated tissue interaction system under the physiologic condition. Dissecting the role of neuropeptides in this system may also reveal as yet obscure neural mechanisms of hair growth control. OBJECTIVE: The purpose of this study was to investigate the effect of SP on human hair growth using a recently described model in which isolated hair follicles are grown in vitro. METHODS: After the healthy human hair follicles without any visible damage were collected, they were cultured in DMEM with several combination of supplements including insulin, hydrocortisone, sodium selenite, human transferrin, fetal bovine serum at 37 degrees C in an atmosphere of 5% CO2 /95% air incubator, and SP was added to the media. The culture media were supplemented with final concentration of 10(-6),10(-7),10(-8) M SP dissolved in DMEM. The results were evaluated by measuring linear hair fiber growth and hair follicle morphology on light microscopy and electron microscopy and by measuring radioisotope uptake of [methyl-3H] thymidine and [U-14C] leucine of hair follicle. RESULTS: The following results were obtained from this study. 1. SP did not have an statistically significant effect on the rate of linear hair growth in cultured hair follicles. However, it prolonged the anagen stage of hair cycle. 2. We could not find morphological differences of hair follicles cultured in SP groups compared with those cultured in control group. 3. DNA and protein synthesis in hair follicles increased steadily for 5 days of culture. CONCLUSION: From the results, we can conclude that SP has growth-stimulatory effect and especially prolongs the duration of anagen phase without affecting the rate of linear hair growth.

Growth Factors Influencing the Morphology and Growth Rate of Hair Follicles in a Human Hair Organ Culture / 대한피부과학회지

BACKGROUND: In order to study hair biology, a hair organ culture system is necessary. However satisfactory hair culture systems have not been established. OBJECTIVE: The purpose of this study was to examine the effectiveness of growth factors and to establish a hair organ culture system for studying hair biology and to evaluate the effectiveness of growth factors. METHOD: After the healthy human anagen hair follicles were collected without any visible damage, they were cultured in William E medium with several combinations of growth factors including insulin, hydrocortisone, sodium selenite, human transfemn, fetal calf serum and epidermal growth factor at 37C in an atmosphere of 5% CO2/air incubation. The culture medium was changed every 3 days. The results were evaluated by measuring hair growth and hair follicle morphology. RESULTS: The results of this study are summarized as follows; 1) In the medium composed of insulin, hydrocortisone,sodium selenite and human transferrin, the human hair follicles continued to grow at an in vivo rate of 0.3mm in a day over 10 days without change of gross and microscopic morphology. 2) In the medium containing insulin and/or hydrocortisone the growing rate of the human hair follicles was similar to that in vivo, but the follicles revealed premature entry into catagen at 2-6 days in the culture macroscopically and microscopically. 3) Adding fetal calf serum to the above medium made the hair follicles retain the freshly isolated hair follicles morphology for 10 days in culture, even though they grew somewhat slower than the in vivo rate from 6 days in culture. 4) The effectiveness of EGF mimics the in vivo depilation of EGF in sheep. CONCLUSION: To supplement insulin, hydrocortisone, sodium selenite, transferrin as growth factors, William E medium was necessary for maintenance of an in vivo growth rate and the morphology the anagen hair follicles. This culture system is not enough, but it might be useful for investigation of the physiology, biology of hair follicles as well as pharmacology and toxicology in hair.

Application of Benzothiazolyl-2-aminoazo-4-methyphenyl to Determination of Trace Titanium in Human Hair by Spectrophotometry / 环境与健康杂志

Objective To improve the performance of triazene reagent, the synthesis of benzothiazolyl_2_aminoazo_4_methyphenyl (BTDAPMP) and its color reaction with titanium were studied in this paper. Methods BTDAPMP was applied to determination of trace titanium in human hair by spectrophotometry. Results In the presence of cetylpyridiniumbromid (CPB), Ti(Ⅳ) reacted with BTDAPMP to form a stable complex in a HAc_NaAc buffer solution at pH 5.5. The ratio of the amount of Ti(Ⅳ): BTDAPMP in the complex was found to 1∶2. The chromogenic reaction was completed within 5 min, and a steady color reaction was maintained for at least 4 h. In the color reaction, the apparent molar absorptivity was 1.21?10 5 L/(mol?cm) at 625 nm wavelength, Beers law was obeyed in the concentration range of 0～0.24 mg/L for Ti(Ⅳ). In the determination of trace Ti(Ⅳ) in human hair, the relative standard deviation (RSD) was less than 5% (n=7), the detection limit was 1.06?10-9 g/ml. Conclusion This method was highly sensitive and selective in determination of trace Ti(Ⅳ) in human hair.

Determination of Phosphorus in Human Hair by Spectrophotometry of Phosphomolybdenum Blue / 昆明医科大学学报

This paper reported a method of determination of phosphorus in human hair by Spectrophotometry of phosphomolybdenum Blue.Samples were decomposed by means of dry ashing.Vitamin C was used as a reducing agent.The conditions of ashing and colouration of phosphomolybdehum Blue,the measurement wavelength and the confidence of this meth od were also studied.

Traços de metais em cabelos humanos / Traces of metals in human hair

Foram determinadas concentração de cálcio, magnésio, zinco, potássio, ferro e cobre em cabelos humanos, por espectromia de absorção atômica, pelo método convencional com chama. As amostras foram colhidas no Vale do Ribeira, São Paulo, Brasil, cuja população vive em ambiente agrário e litorâneo, longe de concentrações industriais, sendo por isso dificil atribuir à poluição ambiental e intoxicações a presença dos metais encontrados. Foram estudadas interferências devidas ao tratamento químico de mineralização das amostras (AU).