Development and certification of reference standards for phenolic content in biologicals, based on comparison of results obtained by GLC, HPLC, spectrophotometric, and colorimetric methods

Phenol is used as a preservative in a number of biological products. Methods that are used for quantitative determination of phenol differ a lot. Current requirements for accredited laboratories include continuous internal quality control. Reference standards with a certified content of the analyte are an effective metrological tool for ensuring such control. The aim of the study was to develop and certify reference standards for phenolic content in biological products, based on comparison of results obtained by GLC, HPLC, spectrophotometric, and colorimetric methods. Materials and methods: diluent for allergens by (candidate reference standard), 2.5 and 5 mg/mL phenol solutions, and 2.5 mg/mL 2-phenoxyethanol solution were used in the study. The experiments were performed using spectrophotometric, colorimetric, HPLC, and GLC procedures. The statistical analysis of results included calculation of the arithmetic mean, standard deviation, coefficient of variation, and analysis of variance with Student’s t-test and Fisher’s F-test. Results: the results of phenolic content determination by the spectrophotometric, colorimetric, and HPLC methods were statistically comparable. The F value obtained for equal sample sizes (n = 40) was F = 0.9343, given the critical value Fcrit = 3.96. A reference standard certified by one of these methods can be used to control the consistency of phenol determination by a relevant method. The results of phenolic content determination by the GLC method showed statistically significantly differences: F = 17.47, given Fcrit = 3.96, which demonstrated the need for certification of another reference standard. Conclusions: two reference standards were certified in the study: reference standard 42-28-449 with the certified phenolic content of 2.56‒3.32 mg/mL, to be used with the spectrophotometric, colorimetric, and HPLC methods; and reference standard 42-28-451 with the certified phenolic content of 2.92‒3.28 mg/mL, to be used with the GLC method.

Evaluation of Some Biochemical Parameters of Wistar Rats Induced by Staphylococcus aureus Isolated from Pneumonia Patients

The effect and extent of changes in some biochemical parameters associated with pneumonia caused by Staphylococcus aureus were investigated in serum samples of Wistar rats. 0ne thousand five serum samples were collected randomly. The serum samples were tested for sodium, potassium, urea, creatinine and chloride by colorimetric methods. The concentrations of sodium ranged from 133.6±4.615 to 143.8±6.906, potassium values ranged from 5.78±1.26 to 8.02±0.779, urea gave a range of 10.143±0.69 to 14.444±2.404, chloride values ranged from 94.8±2.683 to 104.142±8.49, while creatinine values ranged from 0.489±0.033 to 1.7±2.404. The results indicated that Staphylococcus aureus has a significant effect on the electrolyte balance causing hyperkalemia and hyponatremia when compared to normal blood value. It had a remarkable effect on creatinine level with only slight effect on urea. There is need to monitor the electrolyte levels in Staphylococcus aureus infection since alteration in the electrolyte levels could be harmful to health.

ACCUMULATION OF LEAD, CADMIUM AND SULPHUR IN PASTURE GRASSES GROWING ALONG TRAFFIC HIGHWAY AND INDUSTRIAL LAYOUT IN SOUTH EASTERN NIGERIA

Possible uptake of lead, cadmium and sulphur by ruminants from three pasture grasses, Penisetum purpureum, Panicum repens and Cynodom dactylon growing along traffic highway and industrial estate in Akwa Ibom state was investigated. Concentration of the heavy metals and sulphur in the grasses were determined by atomic absorption spectroscopy and colorimetric methods respectively. P. repens from the traffic highway contained the highest amount of lead (56.5µg g-1) and sulphur (681 ppm dry weight) which were significantly (p<0.05) higher than those from industrial layout (36.45µg g-1, Pb and 545 ppm sulphur respectively). The highest content of cadmium (1.6µg g1) was obtained from P. repens and C. dactylon from the same location of the traffic highway. The concentration of the contaminants in all the grasses from industrial layout and traffic highway were higher (p<0.05) than those from arable farm land and rural village which made up the control treatment. The results provide reliable information on the possible dangers ruminant animals are exposed to by grazing forages along traffic highways and around industries.

Ultra-sensitive and selective determination of a phenolic food additive using protein capped gold nanoclusters: a dual in-line fluorometric and colorimetric sensing probe

The application of red luminescence BSA-AuNCs towards the selective determination of food additive tert-butylhydroquinone (TBHQ) was demonstrated by both fluorometric and colorimetric methods.