Sequential chromatogram ratio technique: evaluation of the effects of retention time precision, adsorption isotherm linearity, and detector linearity on qualitative and quantitative analysis

1992 ◽  
Vol 64 (5) ◽  
pp. 489-496 ◽  
Author(s):  
Timothy J. Bahowick ◽  
Robert E. Synovec
2020 ◽  
Vol 12 (2) ◽  
pp. 157
Author(s):  
Rahma Dona

Hydroquinone is a chemical compound widely used in cosmetics that acts as a removal of black spots/spots on the face. The use of hydroquinone in cosmetics, according to BPOM regulations, is only allowed with a maximum level of 2%. Excessive use of hydroquinone can cause pigment abnormalities in the face. The materials used in this study were hydroquinone BPFI, 96% ethanol, absolute ethanol, sodium sulfate, methanol (HPLC grade), aquadest, ethyl acetate, and face cream samples (X and Y). Qualitative and quantitative analysis of hydroquinone content in both face cream samples was carried out by TLC and HPLC methods. The results of the qualitative analysis by TLC on both face cream samples (X and Y creams) showed that both samples had the same Rf value 1as the standard hydroquinone Rf while the HPLC chromatogram results of both samples had the same retention time as the standard hydroquinone. Simultaneously, the results of quantitative analysis on cream X samples contained hydroquinone of 3.06% and Y cream of 4.15%. From these results, both face cream samples positive contained hydroquinone with levels> 2%.


INFO ARTHA ◽  
2017 ◽  
Vol 2 ◽  
pp. 56-79
Author(s):  
NFN Khusnaini ◽  
Agung Widi Hatmoko

Attitudes towards tax compliance (willingness to comply) Indonesian society is still low. Required an innovative tax dissemination to increase it. The purpose of this study was to determine whether the tax dissemination based on Fogg Behavioral Model (FBM) approach may increase wiliingness to comply. The FBM based tax dissemination asserts that for a person to perform a target behavior, which is a willingness to comply, he or she must be sufficiently motivated, have the ability to perform the behavior, and be trigerred, to perform the behavior. This research is a combination of qualitative and quantitative analysis of statistical data results of the questionnaire, interviews, and observations of the respondent and the experimental process of dissemination. The method used in this study is a quasi experimental with patterns of nonequivalent control group (pretest-post which is not equivalent). Based on the results of data analysis, interviews and observations of the respondent and the experiment, this research showed that theFBMbasedtaxdissemination hasapositiveimpactto willingnesstocomplyofthetaxpayers. 


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