求翻译：取本品 ，加水溶解并定量稀释制成每1ml中含20mg的溶液，作为供试品溶液；另取新霉胺对照品，加水溶解并定量稀释制成每1ml中含0.4mg的溶液，作为对照品溶液。照鉴别（2）项下的薄层色谱法检查。供试品溶液所显新霉胺的斑点的颜色与对照溶液主斑点的颜色比较，不得更深是什么意思？

Take this product, made from dissolved and quantitative dilution with water solution of 20mg per 1ml, as a solution of test articles; the other new penicillamine reference substance, add water and dissolved solution for quantitative dilution made from 0.4mg per 1ml, as a reference substance solution. According to the identification of (2) thin-layer chromatography under check. Solution of test articles for the new color of penicillamine spots with the reference solution comparison of the main spots of color, not more