Direct thermal decomposition mercury analysis is an efficient technique for determination of mercury in facial whitening creams. The analysis can be performed without any sample preparation. The samples can be weighed and placed directly into the analyzer. Thus there is no chemical waste produced in sample preparation. The time and energy used in sample digestion are saved as well. The calibration curve between mercury absorbance in terms of peak height and weight of standard mercury in the range of 0.1-10 ng was created. The calibration curve was linear followed the equation y=2.003x10-2X– 5.14x10-4 with coefficient of determination (R2) 0.9991. The precision in term of repeatability were 14% and 5.9% rsd (n=3) at 1.2 and 868 µg kg-1 respectively. The recoveries were between 88-110%. The detection limit (LOD) was 0.1 µg kg-1 (3sd/m n=10). The amount of mercury detected in 12 whitening cream samples sold in Chonburi province during the year 2019 were within the safety standard permitted in general cosmetics under the notification of the Ministry of Public except two samples were over the permitted standard.

This study aimed to investigate the relationship between corporate governance and financial ratio with the performance of companies listed on the stock exchange of Thailand with an excellent score. The data were collected from annual registration statement (Form 56-1) of 191 companies from 2016 to 2020. Descriptive statistics such as mean percentage standard deviation and Inferential statistics such as Pearson’s Correlation Coefficient and Multiple Regression Analysis were used to examine the relationship. The results showed that 1) Corporate Governance namely Board size the ratio of independent director and Managerial Ownership positively corelated with firm performance. 2) Leverage Ratios (Financial Ratio) namely Debt to asset ratio and Debt to equity ratio negatively corelated with firm performance but Interest coverage ratio positively corelated with performance

A simple flow injection analytical system for an automatic determination of phosphate in water samples using the molybdenum blue method was developed. Samples were injected and mixed with ascorbic acid used as a reducing agent. The absorbance of the resulting molybdenum blue complex was measured at 880 nm by a spectrophotometer. The optimal conditions of this system were 2 mL/min of carrier flow rate 1000 μL of sample volume 60 centimeters of mixing tube length and 0.020 mol/L of ascorbic acid. The proposed method showed reliability high sensitivity spend small amount of reagents and samples and fast sample throughput (52 samples/hour). The limit of detection (LOD) was 0.015 mg P/L of phosphate. Precision obtained injecting a phosphate standard solution of 0.50 mg P/L (n=10) was 1.81%. This system can be applied to determination of phosphate content in surface water samples in Lopburi province by comparing with a standard method. It was found that obtained from the developed system agreed well with the standard method using the pair t-test (tstat 0.04 < tcrit 2.36). This flow injection analysis system has no effect from arsenate and silicate interference for the analysis of natural water samples.

The development of students mathematical ideas of under

The purpose of this research the study of the potential of Suphanburi area for planting investment. In which the researcher has studied the soil data set that is different in each area of Suphanburi. That is quite diverse if divided by each district in Suphanburi province themselves from the basic information report in Suphanburi and the agricultural information of Suphanburi for the year 2017 when comparing with the soil set of Suphanburi it can be seen that the cultivation is quite comprehensive all. Although there are cultivated plants in Suphanburi farmers must consider the amount of water sufficient for cultivation. Topsoil maintenance in the case of repeated planting of crops in 1 year to obtain quality produce and prices. At times the agricultural market prices dropped. Farmers will have to modify the cultivation to meet the market demand. Or the cultivation of plants by considering the amount of water that is used in the cultivation as well.