add concentration

• 酸浓度

add concentration的用法和样例：

例句

1. The concentration ofL-serine and formaldehyde were determined by chromatic acid colorimetry.
   采用铬变酸比色法测定甲醛和丝氨酸浓度。
2. Humic acid had significant photosensitization on tetramethrin,and itsphotosensitization increased rapidly as the humic acid concentration increased.
   腐殖酸对胺菊酯光敏化作用显著，并随腐殖酸浓度的增加而迅速增强。